diff --git a/api/globalconfig/types.go b/api/globalconfig/types.go
index 4b9579414..ed4f3c575 100644
--- a/api/globalconfig/types.go
+++ b/api/globalconfig/types.go
@@ -56,9 +56,9 @@ type Go struct {
 }
 
 type ModbusProxy struct {
-	Port            int
-	ReadOnly        string `yaml:",omitempty" json:",omitempty"`
-	modbus.Settings `mapstructure:",squash" yaml:",inline,omitempty" json:",omitempty"`
+	Port            int    `json:"port"`
+	ReadOnly        string `yaml:",omitempty" json:"readonly,omitempty"`
+	modbus.Settings `mapstructure:",squash" yaml:",inline,omitempty" json:"settings,omitempty"`
 }
 
 var _ api.Redactor = (*Hems)(nil)
diff --git a/assets/js/components/Config/DeviceModal/Modbus.vue b/assets/js/components/Config/DeviceModal/Modbus.vue
index d4c4eb6c5..9afc4d0b8 100644
--- a/assets/js/components/Config/DeviceModal/Modbus.vue
+++ b/assets/js/components/Config/DeviceModal/Modbus.vue
@@ -4,41 +4,41 @@
 		id="modbusTcpIp"
 		:label="$t('config.modbus.connection')"
 		:help="
-			connection === 'tcpip'
+			connection === MODBUS_CONNECTION.TCPIP
 				? $t('config.modbus.connectionHintTcpip')
 				: $t('config.modbus.connectionHintSerial')
 		"
 	>
 		<div class="btn-group" role="group">
 			<input
-				id="modbusTcpIp"
+				:id="formId('modbusTcpIp')"
 				v-model="connection"
 				type="radio"
 				class="btn-check"
-				name="modbusConnection"
+				:name="formId('modbusConnection')"
 				value="tcpip"
 				tabindex="0"
 				autocomplete="off"
 			/>
-			<label class="btn btn-outline-primary" for="modbusTcpIp">
+			<label class="btn btn-outline-primary" :for="formId('modbusTcpIp')">
 				{{ $t("config.modbus.connectionValueTcpip") }}
 			</label>
 			<input
-				id="modbusSerial"
+				:id="formId('modbusSerial')"
 				v-model="connection"
 				type="radio"
 				class="btn-check"
-				name="modbusConnection"
+				:name="formId('modbusConnection')"
 				value="serial"
 				tabindex="0"
 				autocomplete="off"
 			/>
-			<label class="btn btn-outline-primary" for="modbusSerial">
+			<label class="btn btn-outline-primary" :for="formId('modbusSerial')">
 				{{ $t("config.modbus.connectionValueSerial") }}
 			</label>
 		</div>
 	</FormRow>
-	<FormRow id="modbusId" :label="$t('config.modbus.id')">
+	<FormRow v-if="!hideModbusId" id="modbusId" :label="$t('config.modbus.id')">
 		<PropertyField
 			id="modbusId"
 			property="id"
@@ -49,14 +49,14 @@
 			@change="$emit('update:id', $event.target.value)"
 		/>
 	</FormRow>
-	<div v-if="connection === 'tcpip'">
+	<div v-if="connection === MODBUS_CONNECTION.TCPIP">
 		<FormRow
-			id="modbusHost"
+			:id="formId('modbusHost')"
 			:label="$t('config.modbus.host')"
 			:help="$t('config.modbus.hostHint')"
 		>
 			<PropertyField
-				id="modbusHost"
+				:id="formId('modbusHost')"
 				property="host"
 				type="String"
 				class="me-2"
@@ -65,9 +65,9 @@
 				@change="$emit('update:host', $event.target.value)"
 			/>
 		</FormRow>
-		<FormRow id="modbusPort" :label="$t('config.modbus.port')">
+		<FormRow :id="formId('modbusPort')" :label="$t('config.modbus.port')">
 			<PropertyField
-				id="modbusPort"
+				:id="formId('modbusPort')"
 				property="port"
 				type="Int"
 				class="me-2 w-50"
@@ -78,7 +78,7 @@
 		</FormRow>
 		<FormRow
 			v-if="showProtocolOptions"
-			id="modbusTcp"
+			:id="formId('modbusTcp')"
 			:label="$t('config.modbus.protocol')"
 			:help="
 				protocol === 'tcp'
@@ -88,29 +88,29 @@
 		>
 			<div class="btn-group" role="group">
 				<input
-					id="modbusTcp"
+					:id="formId('modbusTcp')"
 					v-model="protocol"
 					type="radio"
 					class="btn-check"
-					name="modbusProtocol"
+					:name="formId('modbusProtocol')"
 					value="tcp"
 					tabindex="0"
 					autocomplete="off"
 				/>
-				<label class="btn btn-outline-primary" for="modbusTcp">
+				<label class="btn btn-outline-primary" :for="formId('modbusTcp')">
 					{{ $t("config.modbus.protocolValueTcp") }}
 				</label>
 				<input
-					id="modbusRtu"
+					:id="formId('modbusRtu')"
 					v-model="protocol"
 					type="radio"
 					class="btn-check"
-					name="modbusProtocol"
+					:name="formId('modbusProtocol')"
 					value="rtu"
 					tabindex="0"
 					autocomplete="off"
 				/>
-				<label class="btn btn-outline-primary" for="modbusRtu">
+				<label class="btn btn-outline-primary" :for="formId('modbusRtu')">
 					{{ $t("config.modbus.protocolValueRtu") }}
 				</label>
 			</div>
@@ -118,12 +118,12 @@
 	</div>
 	<div v-else>
 		<FormRow
-			id="modbusDevice"
+			:id="formId('modbusDevice')"
 			:label="$t('config.modbus.device')"
 			:help="$t('config.modbus.deviceHint')"
 		>
 			<PropertyField
-				id="modbusDevice"
+				:id="formId('modbusDevice')"
 				property="device"
 				type="String"
 				class="me-2"
@@ -132,21 +132,21 @@
 				@change="$emit('update:device', $event.target.value)"
 			/>
 		</FormRow>
-		<FormRow id="modbusBaudrate" :label="$t('config.modbus.baudrate')">
+		<FormRow :id="formId('modbusBaudrate')" :label="$t('config.modbus.baudrate')">
 			<PropertyField
-				id="modbusBaudrate"
+				:id="formId('modbusBaudrate')"
 				property="baudrate"
 				type="Choice"
 				class="me-2 w-50"
 				:choice="baudrateOptions"
 				required
 				:model-value="baudrate || defaultBaudrate"
-				@change="$emit('update:baudrate', $event.target.value)"
+				@change="$emit('update:baudrate', parseInt($event.target.value))"
 			/>
 		</FormRow>
-		<FormRow id="modbusComset" :label="$t('config.modbus.comset')">
+		<FormRow :id="formId('modbusComset')" :label="$t('config.modbus.comset')">
 			<PropertyField
-				id="modbusComset"
+				:id="formId('modbusComset')"
 				property="comset"
 				type="Choice"
 				class="me-2 w-50"
@@ -165,9 +165,13 @@ import FormRow from "../FormRow.vue";
 import PropertyField from "../PropertyField.vue";
 import type { PropType } from "vue";
 import type { ModbusCapability } from "./index";
-type Modbus = "rs485serial" | "rs485tcpip" | "tcpip";
-type ConnectionOption = "tcpip" | "serial";
-type ProtocolOption = "tcp" | "rtu";
+import {
+	MODBUS_BAUDRATE,
+	MODBUS_COMSET,
+	MODBUS_CONNECTION,
+	MODBUS_PROTOCOL,
+	MODBUS_TYPE,
+} from "@/types/evcc";
 
 export default defineComponent({
 	name: "Modbus",
@@ -177,7 +181,7 @@ export default defineComponent({
 			type: Array as PropType<ModbusCapability[]>,
 			default: () => [],
 		},
-		modbus: String as PropType<Modbus>,
+		modbus: String as PropType<MODBUS_TYPE>,
 		host: String,
 		port: [Number, String],
 		id: [Number, String],
@@ -188,6 +192,7 @@ export default defineComponent({
 		defaultId: Number,
 		defaultComset: String,
 		defaultBaudrate: Number,
+		hideModbusId: Boolean,
 	},
 	emits: [
 		"update:modbus",
@@ -198,45 +203,53 @@ export default defineComponent({
 		"update:baudrate",
 		"update:comset",
 	],
-	data(): { connection: ConnectionOption; protocol: ProtocolOption } {
+	data() {
 		return {
-			connection: "tcpip",
-			protocol: "tcp",
+			connection: MODBUS_CONNECTION.TCPIP as MODBUS_CONNECTION,
+			protocol: MODBUS_PROTOCOL.TCP as MODBUS_PROTOCOL,
+			MODBUS_PROTOCOL,
+			MODBUS_CONNECTION,
 		};
 	},
 	computed: {
-		selectedModbus(): Modbus {
-			if (this.connection === "serial") {
-				return "rs485serial";
+		selectedModbus(): MODBUS_TYPE {
+			if (this.connection === MODBUS_CONNECTION.SERIAL) {
+				return MODBUS_TYPE.RS485_SERIAL;
 			}
-			return this.protocol === "rtu" ? "rs485tcpip" : "tcpip";
+			return this.protocol === MODBUS_PROTOCOL.RTU
+				? MODBUS_TYPE.RS485_TCPIP
+				: MODBUS_TYPE.TCPIP;
 		},
 		showConnectionOptions() {
 			return this.capabilities.includes("rs485");
 		},
 		showProtocolOptions() {
-			return this.connection === "tcpip" && this.capabilities.includes("rs485");
+			return (
+				this.connection === MODBUS_CONNECTION.TCPIP && this.capabilities.includes("rs485")
+			);
 		},
 		comsetOptions() {
-			return ["8N1", "8E1", "8N2"].map((v) => {
+			return Object.values(MODBUS_COMSET).map((v) => {
 				return { key: v, name: v };
 			});
 		},
 		baudrateOptions() {
-			return [1200, 9600, 19200, 38400, 57600, 115200].map((v) => {
-				return { key: v, name: `${v}` };
-			});
+			return Object.values(MODBUS_BAUDRATE)
+				.filter((v) => typeof v === "number")
+				.map((v) => {
+					return { key: v, name: `${v}` };
+				});
 		},
 	},
 	watch: {
-		selectedModbus(newValue: Modbus) {
+		selectedModbus(newValue: MODBUS_TYPE) {
 			this.$emit("update:modbus", newValue);
 		},
 		options(newValue: ModbusCapability[]) {
 			this.setProtocolByCapabilities(newValue);
 			this.$emit("update:modbus", this.selectedModbus);
 		},
-		modbus(newValue: Modbus) {
+		modbus(newValue: MODBUS_TYPE) {
 			if (newValue) {
 				this.setConnectionAndProtocolByModbus(newValue);
 			}
@@ -248,24 +261,29 @@ export default defineComponent({
 	},
 	methods: {
 		setProtocolByCapabilities(capabilities: ModbusCapability[]) {
-			this.protocol = capabilities.includes("tcpip") ? "tcp" : "rtu";
+			this.protocol = capabilities.includes("tcpip")
+				? MODBUS_PROTOCOL.TCP
+				: MODBUS_PROTOCOL.RTU;
 		},
-		setConnectionAndProtocolByModbus(modbus?: Modbus) {
+		setConnectionAndProtocolByModbus(modbus?: MODBUS_TYPE) {
 			switch (modbus) {
-				case "rs485serial":
-					this.connection = "serial";
-					this.protocol = "rtu";
+				case MODBUS_TYPE.RS485_SERIAL:
+					this.connection = MODBUS_CONNECTION.SERIAL;
+					this.protocol = MODBUS_PROTOCOL.RTU;
 					break;
-				case "rs485tcpip":
-					this.connection = "tcpip";
-					this.protocol = "rtu";
+				case MODBUS_TYPE.RS485_TCPIP:
+					this.connection = MODBUS_CONNECTION.TCPIP;
+					this.protocol = MODBUS_PROTOCOL.RTU;
 					break;
-				case "tcpip":
-					this.connection = "tcpip";
-					this.protocol = "tcp";
+				case MODBUS_TYPE.TCPIP:
+					this.connection = MODBUS_CONNECTION.TCPIP;
+					this.protocol = MODBUS_PROTOCOL.TCP;
 					break;
 			}
 		},
+		formId(name: string): string {
+			return `${name}-${this.id}`;
+		},
 	},
 });
 </script>
diff --git a/assets/js/components/Config/DeviceModal/SponsorTokenRequired.vue b/assets/js/components/Config/DeviceModal/SponsorTokenRequired.vue
index 587b3ab0c..a1b8c1bcd 100644
--- a/assets/js/components/Config/DeviceModal/SponsorTokenRequired.vue
+++ b/assets/js/components/Config/DeviceModal/SponsorTokenRequired.vue
@@ -5,7 +5,7 @@
 		</a>
 	</div>
 	<div v-else class="alert alert-warning my-4">
-		{{ $t("config.sponsor.tokenRequired") }}
+		{{ $t(feature ? "config.sponsor.tokenRequiredFeature" : "config.sponsor.tokenRequired") }}
 		<a href="#" role="button" class="text-warning" @click.prevent="openModal">
 			{{ $t("config.sponsor.tokenRequiredLearnMore") }}
 		</a>
@@ -19,6 +19,7 @@ export default {
 	name: "SponsorTokenRequired",
 	props: {
 		compact: Boolean,
+		feature: Boolean,
 	},
 	methods: {
 		openModal() {
diff --git a/assets/js/components/Config/DeviceModal/index.ts b/assets/js/components/Config/DeviceModal/index.ts
index 49041e1f3..5de3b4a8f 100644
--- a/assets/js/components/Config/DeviceModal/index.ts
+++ b/assets/js/components/Config/DeviceModal/index.ts
@@ -1,4 +1,4 @@
-import type { DeviceType, MeterTemplateUsage } from "@/types/evcc";
+import type { DeviceType, MODBUS_COMSET, MeterTemplateUsage } from "@/types/evcc";
 import { ConfigType } from "@/types/evcc";
 import api from "@/api";
 
@@ -31,7 +31,7 @@ export type ModbusCapability = "rs485" | "tcpip";
 
 export type ModbusParam = TemplateParam & {
   ID?: string;
-  Comset?: string;
+  Comset?: MODBUS_COMSET;
   Baudrate?: number;
   Port?: number;
 };
diff --git a/assets/js/components/Config/JsonModal.vue b/assets/js/components/Config/JsonModal.vue
index 33f140080..f2981f1b1 100644
--- a/assets/js/components/Config/JsonModal.vue
+++ b/assets/js/components/Config/JsonModal.vue
@@ -1,5 +1,5 @@
 <template>
-	<GenericModal ref="modal" :title="title" @open="open">
+	<GenericModal ref="modal" :title="title" :size="size" @open="open">
 		<p v-if="description || docsLink">
 			<span v-if="description">{{ description + " " }}</span>
 			<a v-if="docsLink" :href="docsLink" target="_blank">
@@ -68,6 +68,7 @@ import GenericModal from "../Helper/GenericModal.vue";
 import api from "@/api";
 import { docsPrefix } from "@/i18n";
 import store from "@/store";
+import deepClone from "@/utils/deepClone";
 
 export default {
 	name: "JsonModal",
@@ -84,6 +85,8 @@ export default {
 		transformReadValues: Function,
 		stateKey: String,
 		saveMethod: { type: String, default: "post" },
+		storeValuesInArray: Boolean,
+		size: { type: String },
 	},
 	emits: ["changed", "open"],
 	data() {
@@ -91,8 +94,8 @@ export default {
 			saving: false,
 			removing: false,
 			error: "",
-			values: {},
-			serverValues: {},
+			values: this.storeValuesInArray ? [] : {},
+			serverValues: this.storeValuesInArray ? [] : {},
 		};
 	},
 	computed: {
@@ -121,7 +124,11 @@ export default {
 			if (this.transformReadValues) {
 				this.serverValues = this.transformReadValues(this.serverValues);
 			}
-			this.values = { ...this.serverValues };
+			// Handle null/undefined values when expecting an array or object
+			if (this.serverValues == null) {
+				this.serverValues = this.storeValuesInArray ? [] : {};
+			}
+			this.values = deepClone(this.serverValues);
 		},
 		async save() {
 			this.saving = true;
@@ -163,13 +170,19 @@ export default {
 			this.removing = false;
 		},
 		trimValues(values) {
-			// extend to recursive when needed in the future
-			return Object.fromEntries(
-				Object.entries(values).map(([key, value]) => [
-					key,
-					typeof value === "string" ? value.trim() : value,
-				])
-			);
+			if (Array.isArray(values)) {
+				for (let index = 0; index < values.length; index++) {
+					values[index] = this.trimValues(values[index]);
+				}
+				return values;
+			} else {
+				return Object.fromEntries(
+					Object.entries(values).map(([key, value]) => [
+						key,
+						typeof value === "string" ? value.trim() : value,
+					])
+				);
+			}
 		},
 	},
 };
diff --git a/assets/js/components/Config/ModbusProxyModal.vue b/assets/js/components/Config/ModbusProxyModal.vue
index f0c67ebed..6a56d5e09 100644
--- a/assets/js/components/Config/ModbusProxyModal.vue
+++ b/assets/js/components/Config/ModbusProxyModal.vue
@@ -1,27 +1,266 @@
 <template>
-	<YamlModal
+	<JsonModal
 		id="modbusProxyModal"
 		:title="$t('config.modbusproxy.title')"
 		:description="$t('config.modbusproxy.description')"
 		docs="/docs/reference/configuration/modbusproxy"
-		:defaultYaml="defaultYaml"
 		endpoint="/config/modbusproxy"
-		removeKey="modbusproxy"
-		size="md"
+		state-key="modbusproxy"
+		store-values-in-array
+		disable-remove
+		data-testid="modbusproxy-modal"
+		size="xl"
 		@changed="$emit('changed')"
-	/>
+	>
+		<template #default="{ values }: { values: ModbusProxy[] }">
+			<div class="mb-3">
+				<SponsorTokenRequired v-if="!isSponsor" feature />
+				<pre class="text-monospace my-5">{{ ASCII_DIAGRAM }}</pre>
+				<div v-for="(c, index) in values" :key="index" data-testid="modbusproxy-connection">
+					<div class="d-block">
+						<hr class="mt-5" />
+						<h5>
+							<div class="inner mb-4">
+								{{ $t("config.modbusproxy.connection", { number: index + 1 }) }}
+							</div>
+						</h5>
+					</div>
+					<div class="row d-inline d-lg-flex mb-3">
+						<div class="col-lg-5" data-testid="evcc-box">
+							<div class="border rounded px-3 pt-4 pb-3">
+								<div class="d-lg-block">
+									<h5 class="box-heading">
+										<div class="inner">evcc</div>
+									</h5>
+								</div>
+								<FormRow
+									:id="formId(index, 'sourcePort')"
+									:label="$t('config.modbus.port')"
+									:help="$t('config.modbusproxy.sourcePortHelp')"
+								>
+									<PropertyField
+										:id="formId(index, 'sourcePort')"
+										v-model="c.port"
+										property="port"
+										type="Int"
+										class="w-50"
+										required
+									/>
+								</FormRow>
+								<FormRow
+									:id="formId(index, 'readonly')"
+									:label="$t('config.modbusproxy.readonly.label')"
+									:help="getReadonlyHelp(c.readonly)"
+								>
+									<SelectGroup
+										:id="formId(index, 'readonly')"
+										v-model="c.readonly"
+										class="w-100"
+										:options="readonlyOptions"
+										transparent
+									/>
+								</FormRow>
+							</div>
+						</div>
+						<div
+							class="col-lg-2 d-none d-lg-flex justify-content-center evcc-gray"
+							style="padding-top: 2.5rem"
+						>
+							<shopicon-regular-arrowright
+								size="l"
+								class="flex-shrink-0"
+							></shopicon-regular-arrowright>
+						</div>
+						<div class="col d-flex d-lg-none justify-content-center evcc-gray my-3">
+							<shopicon-regular-arrowdown
+								size="l"
+								class="flex-shrink-0"
+							></shopicon-regular-arrowdown>
+						</div>
+						<div class="col-lg-5" data-testid="device-box">
+							<div class="border rounded px-3 pt-4 pb-3">
+								<div class="d-lg-block">
+									<h5 class="box-heading">
+										<div class="inner">
+											{{ $t("config.modbusproxy.device") }}
+										</div>
+									</h5>
+								</div>
+								<Modbus
+									:id="index"
+									v-model:baudrate="c.settings.baudrate"
+									v-model:comset="c.settings.comset"
+									v-model:device="c.settings.device"
+									:modbus="getModbus(c.settings)"
+									:host="getHost(c.settings.uri)"
+									:port="getPort(c.settings.uri)"
+									:capabilities="['rs485', 'tcpip']"
+									hide-modbus-id
+									@update:host="(host) => updateHost(host, c.settings)"
+									@update:port="(port) => updatePort(port, c.settings)"
+									@update:modbus="(modbus) => updateModbus(c.settings, modbus)"
+								/>
+							</div>
+						</div>
+					</div>
+					<button
+						type="button"
+						class="d-flex btn btn-sm btn-outline-secondary border-0 align-items-center gap-2 evcc-gray ms-auto"
+						:aria-label="$t('config.general.remove')"
+						tabindex="0"
+						@click="values.splice(index, 1)"
+					>
+						<shopicon-regular-trash
+							size="s"
+							class="flex-shrink-0"
+						></shopicon-regular-trash>
+						{{ $t("config.general.remove") }}
+					</button>
+				</div>
+				<hr class="my-5" />
+				<button
+					type="button"
+					class="d-flex btn btn-sm align-items-center gap-2 mb-5"
+					:class="
+						values.length === 0
+							? 'btn-secondary'
+							: 'btn-outline-secondary border-0 evcc-gray'
+					"
+					data-testid="networkconnection-add"
+					tabindex="0"
+					@click="addConnection(values)"
+				>
+					<shopicon-regular-plus size="s" class="flex-shrink-0"></shopicon-regular-plus>
+					{{ $t("config.modbusproxy.add") }}
+				</button>
+			</div>
+		</template>
+	</JsonModal>
 </template>
 
-<script>
-import YamlModal from "./YamlModal.vue";
-import defaultYaml from "./defaultYaml/modbusproxy.yaml?raw";
+<script lang="ts">
+import "@h2d2/shopicons/es/regular/arrowright";
+import "@h2d2/shopicons/es/regular/arrowdown";
+import "@h2d2/shopicons/es/regular/plus";
+import "@h2d2/shopicons/es/regular/trash";
+import JsonModal from "./JsonModal.vue";
+import {
+	MODBUS_COMSET,
+	MODBUS_CONNECTION,
+	MODBUS_PROTOCOL,
+	MODBUS_PROXY_READONLY,
+	MODBUS_TYPE,
+	type ModbusProxy,
+	type ModbusProxySettings,
+} from "@/types/evcc";
+import ASCII_DIAGRAM from "./modbus-diagram.txt?raw";
+import Modbus from "./DeviceModal/Modbus.vue";
+import PropertyField from "./PropertyField.vue";
+import FormRow from "./FormRow.vue";
+import SponsorTokenRequired from "./DeviceModal/SponsorTokenRequired.vue";
+import SelectGroup from "@/components/Helper/SelectGroup.vue";
+import { defineComponent } from "vue";
 
-export default {
+export default defineComponent({
 	name: "ModbusProxyModal",
-	components: { YamlModal },
+	components: { JsonModal, Modbus, FormRow, PropertyField, SponsorTokenRequired, SelectGroup },
+	props: {
+		isSponsor: Boolean,
+	},
 	emits: ["changed"],
 	data() {
-		return { defaultYaml: defaultYaml.trim() };
+		return {
+			ASCII_DIAGRAM,
+			MODBUS_PROXY_READONLY,
+			MODBUS_CONNECTION,
+			MODBUS_PROTOCOL,
+			MODBUS_TYPE,
+		};
 	},
-};
+	computed: {
+		readonlyOptions() {
+			return Object.values(MODBUS_PROXY_READONLY).map((value) => ({
+				value,
+				name: this.$t(`config.modbusproxy.option.${value}`),
+			}));
+		},
+	},
+	methods: {
+		formId(index: number, name: string) {
+			return `modbusproxy-connection-${index}-${name}`;
+		},
+		getModbus(s: ModbusProxySettings) {
+			if (s.device) {
+				return MODBUS_TYPE.RS485_SERIAL;
+			}
+			return s.rtu ? MODBUS_TYPE.RS485_TCPIP : MODBUS_TYPE.TCPIP;
+		},
+		getReadonlyHelp(readonly = MODBUS_PROXY_READONLY.FALSE): string {
+			return this.$t(`config.modbusproxy.readonly.help.${readonly}`);
+		},
+		addConnection(values: ModbusProxy[]) {
+			const highestPort = values.length > 0 ? Math.max(...values.map((c) => c.port)) : 1501;
+			values.push({
+				port: highestPort + 1,
+				readonly: MODBUS_PROXY_READONLY.FALSE,
+				settings: {
+					uri: ":502",
+					baudrate: 9600,
+					comset: "8N1" as MODBUS_COMSET,
+				},
+			});
+		},
+		getHost(uri?: string) {
+			return uri?.split(":")[0] || "";
+		},
+		getPort(uri?: string) {
+			return uri?.split(":")[1] || "";
+		},
+		updateHost(newHost: string, settings: ModbusProxySettings) {
+			const port = this.getPort(settings.uri);
+			settings.uri = `${newHost}:${port}`;
+		},
+		updatePort(newPort: string | number, settings: ModbusProxySettings) {
+			const host = this.getHost(settings.uri);
+			settings.uri = `${host}:${newPort}`;
+		},
+		updateModbus(settings: ModbusProxySettings, modbus: MODBUS_TYPE) {
+			switch (modbus) {
+				case MODBUS_TYPE.RS485_SERIAL:
+					settings.uri = undefined;
+					settings.rtu = undefined;
+					break;
+				case MODBUS_TYPE.RS485_TCPIP:
+				case MODBUS_TYPE.TCPIP:
+					settings.device = undefined;
+					settings.baudrate = undefined;
+					settings.comset = undefined;
+					settings.rtu = modbus === MODBUS_TYPE.RS485_TCPIP;
+					break;
+			}
+		},
+	},
+});
 </script>
+
+<style scoped>
+h5 {
+	position: relative;
+	display: flex;
+	top: -25px;
+	margin-bottom: -0.5rem;
+	padding: 0 0.5rem;
+	justify-content: center;
+}
+h5.box-heading {
+	top: -34px;
+	margin-bottom: -24px;
+}
+h5 .inner {
+	padding: 0 0.5rem;
+	background-color: var(--evcc-box);
+	font-weight: normal;
+	color: var(--evcc-gray);
+	text-align: center;
+}
+</style>
diff --git a/assets/js/components/Config/defaultYaml/modbusproxy.yaml b/assets/js/components/Config/defaultYaml/modbusproxy.yaml
deleted file mode 100644
index adccb3162..000000000
--- a/assets/js/components/Config/defaultYaml/modbusproxy.yaml
+++ /dev/null
@@ -1,7 +0,0 @@
-#- port: 5021 # proxy port for incoming ModbusTCP requests
-#  uri: 192.0.2.2:502 # device address for downstream requests
-#  rtu: true # optional: use RTU for downstream requests to device
-#- port: 5022 # proxy port for incoming ModbusTCP requests
-#  device: /dev/ttyUSB0 # local device for downstream requests
-#  baudrate: 9600
-#  comset: "8N1"
diff --git a/assets/js/components/Config/modbus-diagram.txt b/assets/js/components/Config/modbus-diagram.txt
new file mode 100644
index 000000000..3c2bc69d1
--- /dev/null
+++ b/assets/js/components/Config/modbus-diagram.txt
@@ -0,0 +1,7 @@
+                                       ┌────────┐
+                         ┌─ network ─> │ device │
+┌────────┐           ┌──────┐          └────────┘
+│ client │ --port--> │ evcc │         
+└────────┘           └──────┘          ┌────────┐
+                         └─ serial --> │ device │
+                                       └────────┘
diff --git a/assets/js/types/evcc.ts b/assets/js/types/evcc.ts
index 38ceb8d56..09db0834d 100644
--- a/assets/js/types/evcc.ts
+++ b/assets/js/types/evcc.ts
@@ -72,7 +72,7 @@ export interface State {
   shm?: ShmConfig;
   sponsor?: Sponsor;
   eebus?: any;
-  modbusproxy?: [];
+  modbusproxy?: ModbusProxy[];
   messaging?: any;
   interval?: number;
   circuits?: Record<string, Circuit>;
@@ -352,6 +352,57 @@ export interface Sponsor {
   fromYaml: boolean;
 }
 
+export enum MODBUS_BAUDRATE {
+  _1200 = 1200,
+  _9600 = 9600,
+  _19200 = 19200,
+  _38400 = 38400,
+  _57600 = 57600,
+  _115200 = 115200,
+}
+
+export enum MODBUS_TYPE {
+  RS485_SERIAL = "rs485serial",
+  RS485_TCPIP = "rs485tcpip",
+  TCPIP = "tcpip",
+}
+
+export enum MODBUS_COMSET {
+  _8N1 = "8N1",
+  _8E1 = "8E1",
+  _8N2 = "8N2",
+}
+
+export enum MODBUS_PROXY_READONLY {
+  FALSE = "false",
+  TRUE = "true",
+  DENY = "deny",
+}
+
+export enum MODBUS_CONNECTION {
+  TCPIP = "tcpip",
+  SERIAL = "serial",
+}
+
+export enum MODBUS_PROTOCOL {
+  TCP = "tcp",
+  RTU = "rtu",
+}
+
+export type ModbusProxy = {
+  port: number;
+  readonly: MODBUS_PROXY_READONLY;
+  settings: ModbusProxySettings;
+};
+
+export interface ModbusProxySettings {
+  uri?: string;
+  rtu?: boolean;
+  device?: string;
+  baudrate?: MODBUS_BAUDRATE;
+  comset?: MODBUS_COMSET;
+}
+
 export interface Notification {
   message: string;
   time: Date;
diff --git a/assets/js/views/Config.vue b/assets/js/views/Config.vue
index c9e4235bf..036b39250 100644
--- a/assets/js/views/Config.vue
+++ b/assets/js/views/Config.vue
@@ -354,13 +354,12 @@
 				<MqttModal @changed="loadDirty" />
 				<NetworkModal @changed="loadDirty" />
 				<ControlModal @changed="loadDirty" />
-				<SponsorModal :error="hasClassError('sponsorship')" @changed="loadDirty" />
 				<HemsModal @changed="yamlChanged" />
 				<ShmModal @changed="loadDirty" />
 				<MessagingModal @changed="yamlChanged" />
 				<TariffsModal @changed="yamlChanged" />
 				<TelemetryModal :sponsor="sponsor" :telemetry="telemetry" />
-				<ModbusProxyModal @changed="yamlChanged" />
+				<ModbusProxyModal :is-sponsor="isSponsor" @changed="loadDirty" />
 				<CircuitsModal
 					:gridMeter="gridMeter"
 					:extMeters="extMeters"
@@ -369,6 +368,7 @@
 				<EebusModal @changed="yamlChanged" />
 				<BackupRestoreModal v-bind="backupRestoreProps" />
 				<PasswordModal update-mode />
+				<SponsorModal :error="hasClassError('sponsorship')" @changed="loadDirty" />
 			</div>
 		</div>
 	</div>
diff --git a/cmd/setup.go b/cmd/setup.go
index 4e73a3c50..59c450e2e 100644
--- a/cmd/setup.go
+++ b/cmd/setup.go
@@ -951,13 +951,33 @@ func configureDevices(conf globalconfig.All) error {
 	return joinErrors(errs...)
 }
 
+// migrateYamlToJson converts a settings value from yaml to json if needed
+func migrateYamlToJson[T any](key string) error {
+	var err error
+	if settings.IsJson(key) {
+		// already JSON, nothing to do
+		return nil
+	}
+
+	var data T
+	if err := settings.Yaml(key, new(T), &data); err == nil {
+		settings.SetJson(key, data)
+		log.INFO.Printf("migrated %s setting to JSON", key)
+	}
+
+	return err
+}
+
 func configureModbusProxy(conf *[]globalconfig.ModbusProxy) error {
-	// migrate settings
 	if settings.Exists(keys.ModbusProxy) {
-		*conf = []globalconfig.ModbusProxy{}
-		if err := settings.Yaml(keys.ModbusProxy, new([]map[string]any), &conf); err != nil {
+		// TODO: delete if not needed any more
+		if err := migrateYamlToJson[[]globalconfig.ModbusProxy](keys.ModbusProxy); err != nil {
 			return err
 		}
+
+		if err := settings.Json(keys.ModbusProxy, &conf); err != nil {
+			return fmt.Errorf("failed to read modbusproxy setting: %w", err)
+		}
 	}
 
 	for _, cfg := range *conf {
diff --git a/i18n/de.json b/i18n/de.json
index 2e782ff3b..30f259a28 100644
--- a/i18n/de.json
+++ b/i18n/de.json
@@ -387,7 +387,24 @@
       "protocolValueTcp": "TCP"
     },
     "modbusproxy": {
-      "description": "Erlaubt mehreren Clients den Zugriff auf ein einzelnes Modbus-Gerät.",
+      "add": "Proxy-Verbindung hinzufügen",
+      "connection": "Verbindung #{number}",
+      "description": "Manche Modbus-Geräte unterstützen nur eine oder sehr wenige Verbindungen. evcc kann als Proxy fungieren und ermöglicht so simultanen Zugriff für mehrere Clients (Hausautomation, Skripte, etc.).",
+      "device": "Gerät",
+      "option": {
+        "deny": "Fehler",
+        "false": "nein",
+        "true": "still"
+      },
+      "readonly": {
+        "help": {
+          "deny": "Schreibzugriff wird mit Modbus-Fehler blockiert.",
+          "false": "Schreibzugriff wird weitergeleitet.",
+          "true": "Schreibzugriff wird ohne Antwort blockiert."
+        },
+        "label": "Nur lesen"
+      },
+      "sourcePortHelp": "Port für eingehende Client-Verbindungen. Muss verfügbar sein.",
       "title": "Modbus-Proxy"
     },
     "mqtt": {
@@ -477,6 +494,7 @@
       "labelToken": "Sponsortoken",
       "title": "Sponsoring",
       "tokenRequired": "Du musst ein Sponsortoken konfigurieren, bevor du dieses Gerät anlegen kannst.",
+      "tokenRequiredFeature": "Diese Funktion erfordert ein Sponsortoken.",
       "tokenRequiredLearnMore": "Mehr erfahren.",
       "tokenRequiredShort": "Kein Sponsortoken konfiguriert.",
       "trialToken": "Testtoken",
diff --git a/i18n/en.json b/i18n/en.json
index e36f3bf8b..a6f0ca002 100644
--- a/i18n/en.json
+++ b/i18n/en.json
@@ -388,7 +388,24 @@
       "protocolValueTcp": "TCP"
     },
     "modbusproxy": {
-      "description": "Allow multiple clients to access a single Modbus device.",
+      "add": "Add proxy connection",
+      "connection": "Connection #{number}",
+      "description": "Some Modbus devices only support a single or very few connections. evcc can act as a proxy, enabling simultaneous access for multiple clients (home automation, scripts, etc.).",
+      "device": "Device",
+      "option": {
+        "deny": "error",
+        "false": "no",
+        "true": "silent"
+      },
+      "readonly": {
+        "help": {
+          "deny": "Write access is blocked with a Modbus error.",
+          "false": "Write access is forwarded.",
+          "true": "Write access is blocked without response."
+        },
+        "label": "Readonly"
+      },
+      "sourcePortHelp": "Port for incoming client connections. Must be available.",
       "title": "Modbus Proxy"
     },
     "mqtt": {
@@ -478,6 +495,7 @@
       "labelToken": "Sponsor token",
       "title": "Sponsorship",
       "tokenRequired": "You must configure a sponsor token before you can create this device.",
+      "tokenRequiredFeature": "This feature requires a sponsor token.",
       "tokenRequiredLearnMore": "Learn more.",
       "tokenRequiredShort": "No sponsor token configured.",
       "trialToken": "trial token",
diff --git a/server/db/settings/setting.go b/server/db/settings/setting.go
index 2e659494c..56ce1299b 100644
--- a/server/db/settings/setting.go
+++ b/server/db/settings/setting.go
@@ -242,6 +242,11 @@ func Yaml(key string, other, res any) error {
 	return DecodeOtherSliceOrMap(other, res)
 }
 
+func IsJson(key string) bool {
+	s, err := String(key)
+	return err == nil && json.Unmarshal([]byte(s), &json.RawMessage{}) == nil
+}
+
 // wrapping Settings into a struct for better decoupling
 type Settings struct{}
 
diff --git a/server/http.go b/server/http.go
index f8503ff93..ae9beeb1a 100644
--- a/server/http.go
+++ b/server/http.go
@@ -292,12 +292,11 @@ func (s *HTTPd) RegisterSystemHandler(site *core.Site, valueChan chan<- util.Par
 
 		// yaml handlers
 		for key, fun := range map[string]func() (any, any){
-			keys.EEBus:       func() (any, any) { return map[string]any{}, eebus.Config{} },
-			keys.Hems:        func() (any, any) { return map[string]any{}, config.Typed{} },
-			keys.Tariffs:     func() (any, any) { return map[string]any{}, globalconfig.Tariffs{} },
-			keys.Messaging:   func() (any, any) { return map[string]any{}, globalconfig.Messaging{} },       // has default
-			keys.ModbusProxy: func() (any, any) { return []map[string]any{}, []globalconfig.ModbusProxy{} }, // slice
-			keys.Circuits:    func() (any, any) { return []map[string]any{}, []config.Named{} },             // slice
+			keys.EEBus:     func() (any, any) { return map[string]any{}, eebus.Config{} },
+			keys.Hems:      func() (any, any) { return map[string]any{}, config.Typed{} },
+			keys.Tariffs:   func() (any, any) { return map[string]any{}, globalconfig.Tariffs{} },
+			keys.Messaging: func() (any, any) { return map[string]any{}, globalconfig.Messaging{} }, // has default
+			keys.Circuits:  func() (any, any) { return []map[string]any{}, []config.Named{} },       // slice
 		} {
 			other, struc := fun()
 			routes[key] = route{Method: "GET", Pattern: "/" + key, HandlerFunc: settingsGetStringHandler(key)}
@@ -307,10 +306,11 @@ func (s *HTTPd) RegisterSystemHandler(site *core.Site, valueChan chan<- util.Par
 
 		// json handlers
 		for key, fun := range map[string]func() any{
-			keys.Network: func() any { return new(globalconfig.Network) }, // has default
-			keys.Mqtt:    func() any { return new(globalconfig.Mqtt) },    // has default
-			keys.Shm:     func() any { return new(shm.Config) },
-			keys.Influx:  func() any { return new(globalconfig.Influx) },
+			keys.Network:     func() any { return new(globalconfig.Network) },       // has default
+			keys.Mqtt:        func() any { return new(globalconfig.Mqtt) },          // has default
+			keys.ModbusProxy: func() any { return new([]globalconfig.ModbusProxy) }, // slice
+			keys.Shm:         func() any { return new(shm.Config) },
+			keys.Influx:      func() any { return new(globalconfig.Influx) },
 		} {
 			routes["update"+key] = route{Method: "POST", Pattern: "/" + key, HandlerFunc: settingsSetJsonHandler(key, valueChan, fun)}
 			routes["delete"+key] = route{Method: "DELETE", Pattern: "/" + key, HandlerFunc: settingsDeleteJsonHandler(key, valueChan, fun())}
diff --git a/server/http_global_settings_handler.go b/server/http_global_settings_handler.go
index 3f9a25aa1..8708752c6 100644
--- a/server/http_global_settings_handler.go
+++ b/server/http_global_settings_handler.go
@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"io"
 	"net/http"
+	"reflect"
 	"strconv"
 	"strings"
 	"time"
@@ -83,9 +84,12 @@ func settingsSetJsonHandler(key string, valueChan chan<- util.Param, newStruc fu
 
 		oldStruc := newStruc()
 		if err := settings.Json(key, &oldStruc); err == nil {
-			if err := mergeMaskedAny(oldStruc, struc); err != nil {
-				jsonError(w, http.StatusInternalServerError, err)
-				return
+			// Skip merge for slices - they should be replaced entirely
+			if reflect.ValueOf(struc).Elem().Kind() != reflect.Slice {
+				if err := mergeMaskedAny(oldStruc, struc); err != nil {
+					jsonError(w, http.StatusInternalServerError, err)
+					return
+				}
 			}
 		}
 
diff --git a/tests/config-modbusproxy-migrate.sql b/tests/config-modbusproxy-migrate.sql
new file mode 100644
index 000000000..ab39450f9
--- /dev/null
+++ b/tests/config-modbusproxy-migrate.sql
@@ -0,0 +1,19 @@
+BEGIN;
+
+CREATE TABLE `settings` (
+    `key` text
+  , `value` text
+  , PRIMARY KEY(`key`)
+);
+
+INSERT INTO settings("key", value) VALUES('modbusproxy', '- port: 5021
+  uri: 192.0.2.2:502
+- port: 5022
+  device: /dev/ttyUSB0
+  baudrate: 9600
+  comset: "8N1"
+- port: 5023
+  uri: 192.0.2.3:502
+  rtu: true');
+
+COMMIT;
\ No newline at end of file
diff --git a/tests/config-modbusproxy.spec.ts b/tests/config-modbusproxy.spec.ts
new file mode 100644
index 000000000..63b27c0aa
--- /dev/null
+++ b/tests/config-modbusproxy.spec.ts
@@ -0,0 +1,139 @@
+import { test, expect } from "@playwright/test";
+import { start, stop, baseUrl, restart } from "./evcc";
+import { expectModalVisible, enableExperimental, expectModalHidden } from "./utils";
+
+test.use({ baseURL: baseUrl() });
+test.describe.configure({ mode: "parallel" });
+
+const CONFIG_MODBUSPROXY_MIGRATE = "config-modbusproxy-migrate.sql";
+
+test.afterEach(async () => {
+  await stop();
+});
+
+test.describe("modbusproxy", async () => {
+  test("modbusproxy not configured", async ({ page }) => {
+    await start();
+    await page.goto("/#/config");
+    await enableExperimental(page, false);
+
+    const modbusproxyCard = page.getByTestId("modbusproxy");
+
+    await expect(modbusproxyCard).toBeVisible();
+    await expect(modbusproxyCard).toContainText(["Configured", "no"].join(""));
+  });
+
+  test("modbusproxy via ui", async ({ page }) => {
+    await start();
+    await page.goto("/#/config");
+    await enableExperimental(page, false);
+
+    // add connection
+    const modbusproxyCard = page.getByTestId("modbusproxy");
+
+    await modbusproxyCard.getByRole("button", { name: "edit" }).click();
+    const modal = await page.getByTestId("modbusproxy-modal");
+    await expectModalVisible(modal);
+
+    await expect(modal).toContainText("This feature requires a sponsor token.");
+
+    await modal.getByRole("button", { name: "Add proxy connection" }).click();
+    await expect(modal).toContainText("Connection #1");
+
+    const evccBox = modal.getByTestId("evcc-box");
+    const deviceBox = modal.getByTestId("device-box");
+
+    const evccPort = evccBox.getByLabel("Port");
+    await expect(evccPort).toHaveValue("1502");
+    await evccPort.fill("501");
+
+    await expect(evccBox.getByLabel("no")).toBeChecked();
+    await evccBox.getByLabel("error").click();
+
+    await expect(deviceBox.getByText("Network")).toBeChecked();
+    await deviceBox.getByLabel("IP address or hostname").fill("127.0.0.1");
+
+    const devicePort = deviceBox.getByLabel("Port");
+    await expect(devicePort).toHaveValue("502");
+    await devicePort.fill("602");
+
+    await expect(deviceBox.getByText("TCP")).toBeChecked();
+    await deviceBox.getByText("RTU").click();
+
+    // validate connection
+    await modal.getByRole("button", { name: "Save" }).click();
+    await expectModalHidden(modal);
+
+    await expect(modbusproxyCard).toContainText(["Amount", "1"].join(""));
+
+    // restart button appears
+    const restartButton = await page
+      .getByTestId("bottom-banner")
+      .getByRole("button", { name: "Restart" });
+    await expect(restartButton).toBeVisible();
+
+    await restart();
+    await page.reload();
+
+    await modbusproxyCard.getByRole("button", { name: "edit" }).click();
+
+    await expect(evccBox.getByLabel("Port")).toHaveValue("501");
+    await expect(evccBox.getByLabel("error")).toBeChecked();
+    await expect(deviceBox.getByText("Network")).toBeChecked();
+    await deviceBox.getByLabel("IP address or hostname").fill("127.0.0.1");
+    await expect(deviceBox.getByLabel("Port")).toHaveValue("602");
+    await expect(deviceBox.getByText("RTU")).toBeChecked();
+
+    // remove connection
+    await modal.getByRole("button", { name: "Remove" }).click();
+    await expect(modal).not.toContainText("Connection #1");
+  });
+
+  test("modbusproxy via db (yaml to json migration)", async ({ page }) => {
+    await start(undefined, CONFIG_MODBUSPROXY_MIGRATE);
+    await page.goto("/#/config");
+    await enableExperimental(page, false);
+
+    const modbusproxyCard = page.getByTestId("modbusproxy");
+    await expect(modbusproxyCard).toContainText(["Amount", "3"].join(""));
+
+    await modbusproxyCard.getByRole("button", { name: "edit" }).click();
+    const modal = await page.getByTestId("modbusproxy-modal");
+    await expectModalVisible(modal);
+
+    const connections = modal.getByTestId("modbusproxy-connection");
+    await expect(connections).toHaveCount(3);
+
+    // Connection #1: 192.0.2.2:502 (TCP)
+    const connection1 = connections.nth(0);
+    await expect(connection1).toContainText("Connection #1");
+    await expect(connection1.getByTestId("evcc-box").getByLabel("Port")).toHaveValue("5021");
+    const device1 = connection1.getByTestId("device-box");
+    await expect(device1.getByText("Network")).toBeChecked();
+    await expect(device1.getByLabel("IP address or hostname")).toHaveValue("192.0.2.2");
+    await expect(device1.getByLabel("Port")).toHaveValue("502");
+    await expect(device1.getByText("TCP")).toBeChecked();
+
+    // Connection #2: /dev/ttyUSB0 9600 8N1
+    const connection2 = connections.nth(1);
+    await expect(connection2).toContainText("Connection #2");
+    await expect(connection2.getByTestId("evcc-box")).toBeVisible();
+    await expect(connection2.getByTestId("evcc-box").getByLabel("Port")).toBeVisible();
+    await expect(connection2.getByTestId("evcc-box").getByLabel("Port")).toHaveValue("5022");
+    const device2 = connection2.getByTestId("device-box");
+    await expect(device2.getByText("Serial")).toBeChecked();
+    await expect(device2.getByLabel("Device")).toHaveValue("/dev/ttyUSB0");
+    await expect(device2.getByLabel("Baud rate")).toHaveValue("9600");
+    await expect(device2.getByLabel("ComSet")).toHaveValue("8N1");
+
+    // Connection #3: 192.0.2.3:502 (RTU)
+    const connection3 = connections.nth(2);
+    await expect(connection3).toContainText("Connection #3");
+    await expect(connection3.getByTestId("evcc-box").getByLabel("Port")).toHaveValue("5023");
+    const device3 = connection3.getByTestId("device-box");
+    await expect(device3.getByText("Network")).toBeChecked();
+    await expect(device3.getByLabel("IP address or hostname")).toHaveValue("192.0.2.3");
+    await expect(device3.getByLabel("Port")).toHaveValue("502");
+    await expect(device3.getByText("RTU")).toBeChecked();
+  });
+});
diff --git a/util/modbus/modbus.go b/util/modbus/modbus.go
index 907231ec9..2283faa1f 100644
--- a/util/modbus/modbus.go
+++ b/util/modbus/modbus.go
@@ -33,12 +33,14 @@ type TcpSettings struct {
 
 // Settings contains the ModBus settings
 type Settings struct {
-	ID                  uint8  `json:",omitempty" yaml:",omitempty"`
-	SubDevice           int    `json:",omitempty" yaml:",omitempty"`
-	URI, Device, Comset string `json:",omitempty" yaml:",omitempty"`
-	Baudrate            int    `json:",omitempty" yaml:",omitempty"`
-	UDP                 bool   `json:",omitempty" yaml:",omitempty"`
-	RTU                 *bool  `json:",omitempty" yaml:",omitempty"`
+	ID        uint8  `json:"id,omitempty" yaml:",omitempty"`
+	SubDevice int    `json:"subdevice,omitempty" yaml:",omitempty"`
+	URI       string `json:"uri,omitempty" yaml:",omitempty"`
+	Device    string `json:"device,omitempty" yaml:",omitempty"`
+	Comset    string `json:"comset,omitempty" yaml:",omitempty"`
+	Baudrate  int    `json:"baudrate,omitempty" yaml:",omitempty"`
+	UDP       bool   `json:"udp,omitempty" yaml:",omitempty"`
+	RTU       *bool  `json:"rtu,omitempty" yaml:",omitempty"`
 }
 
 // Protocol identifies the wire format from the RTU setting