diff --git a/api/error.go b/api/error.go
index 58ba7670e..3a05b207b 100644
--- a/api/error.go
+++ b/api/error.go
@@ -11,6 +11,9 @@ var ErrMustRetry = errors.New("must retry")
 // ErrSponsorRequired indicates that a sponsor token is required
 var ErrSponsorRequired = errors.New("sponsorship required, see https://github.com/evcc-io/evcc#sponsorship")
 
+// ErrMissingCredentials indicates that user/password are missing
+var ErrMissingCredentials = errors.New("missing credentials")
+
 // ErrTimeout is the error returned when a timeout happened.
 // Modeled after context.DeadlineError
 var ErrTimeout error = errTimeoutError{}
diff --git a/vehicle/bmw.go b/vehicle/bmw.go
index 59b9c9f91..846526948 100644
--- a/vehicle/bmw.go
+++ b/vehicle/bmw.go
@@ -44,6 +44,10 @@ func NewBMWMiniFromConfig(brand string, other map[string]interface{}) (api.Vehic
 		return nil, err
 	}
 
+	if cc.User == "" || cc.Password == "" {
+		return nil, api.ErrMissingCredentials
+	}
+
 	v := &BMW{
 		embed: &cc.embed,
 	}
diff --git a/vehicle/carwings.go b/vehicle/carwings.go
index 375309e01..5782468cd 100644
--- a/vehicle/carwings.go
+++ b/vehicle/carwings.go
@@ -52,7 +52,7 @@ func NewCarWingsFromConfig(other map[string]interface{}) (api.Vehicle, error) {
 	}
 
 	if cc.User == "" || cc.Password == "" {
-		return nil, errors.New("missing credentials")
+		return nil, api.ErrMissingCredentials
 	}
 
 	log := util.NewLogger("carwings").Redact(cc.User, cc.Password, cc.VIN)
diff --git a/vehicle/fiat.go b/vehicle/fiat.go
index f11c0b495..971f4b494 100644
--- a/vehicle/fiat.go
+++ b/vehicle/fiat.go
@@ -1,7 +1,6 @@
 package vehicle
 
 import (
-	"errors"
 	"fmt"
 	"strings"
 	"time"
@@ -40,7 +39,7 @@ func NewFiatFromConfig(other map[string]interface{}) (api.Vehicle, error) {
 	}
 
 	if cc.User == "" || cc.Password == "" {
-		return nil, errors.New("missing credentials")
+		return nil, api.ErrMissingCredentials
 	}
 
 	v := &Fiat{
diff --git a/vehicle/ford.go b/vehicle/ford.go
index 51f39c227..3473768b4 100644
--- a/vehicle/ford.go
+++ b/vehicle/ford.go
@@ -56,7 +56,7 @@ func NewFordFromConfig(other map[string]interface{}) (api.Vehicle, error) {
 	}
 
 	if cc.User == "" || cc.Password == "" {
-		return nil, errors.New("missing credentials")
+		return nil, api.ErrMissingCredentials
 	}
 
 	log := util.NewLogger("ford").Redact(cc.User, cc.Password, cc.VIN)
diff --git a/vehicle/hyundai.go b/vehicle/hyundai.go
index fd22dc4f3..900d97183 100644
--- a/vehicle/hyundai.go
+++ b/vehicle/hyundai.go
@@ -1,7 +1,6 @@
 package vehicle
 
 import (
-	"errors"
 	"fmt"
 	"strings"
 	"time"
@@ -39,7 +38,7 @@ func NewHyundaiFromConfig(other map[string]interface{}) (api.Vehicle, error) {
 	}
 
 	if cc.User == "" || cc.Password == "" {
-		return nil, errors.New("missing credentials")
+		return nil, api.ErrMissingCredentials
 	}
 
 	log := util.NewLogger("hyundai").Redact(cc.User, cc.Password, cc.VIN)
diff --git a/vehicle/kia.go b/vehicle/kia.go
index 2e97b4689..23554647c 100644
--- a/vehicle/kia.go
+++ b/vehicle/kia.go
@@ -1,7 +1,6 @@
 package vehicle
 
 import (
-	"errors"
 	"fmt"
 	"strings"
 	"time"
@@ -39,7 +38,7 @@ func NewKiaFromConfig(other map[string]interface{}) (api.Vehicle, error) {
 	}
 
 	if cc.User == "" || cc.Password == "" {
-		return nil, errors.New("missing credentials")
+		return nil, api.ErrMissingCredentials
 	}
 
 	log := util.NewLogger("kia").Redact(cc.User, cc.Password, cc.VIN)
diff --git a/vehicle/nissan.go b/vehicle/nissan.go
index 83e3bdd8d..24b534619 100644
--- a/vehicle/nissan.go
+++ b/vehicle/nissan.go
@@ -44,6 +44,10 @@ func NewNissanFromConfig(other map[string]interface{}) (api.Vehicle, error) {
 		return nil, err
 	}
 
+	if cc.User == "" || cc.Password == "" {
+		return nil, api.ErrMissingCredentials
+	}
+
 	v := &Nissan{
 		embed: &cc.embed,
 	}
diff --git a/vehicle/porsche.go b/vehicle/porsche.go
index b32499954..20158c5b3 100644
--- a/vehicle/porsche.go
+++ b/vehicle/porsche.go
@@ -42,6 +42,10 @@ func NewPorscheFromConfig(other map[string]interface{}) (api.Vehicle, error) {
 		return nil, err
 	}
 
+	if cc.User == "" || cc.Password == "" {
+		return nil, api.ErrMissingCredentials
+	}
+
 	log := util.NewLogger("porsche").Redact(cc.User, cc.Password, cc.VIN)
 	identity := porsche.NewIdentity(log, cc.User, cc.Password)
 
diff --git a/vehicle/psa.go b/vehicle/psa.go
index a52828d54..c130c92f7 100644
--- a/vehicle/psa.go
+++ b/vehicle/psa.go
@@ -81,6 +81,10 @@ func newPSA(log *util.Logger, brand, realm, id, secret string, other map[string]
 		return nil, err
 	}
 
+	if cc.User == "" || cc.Password == "" {
+		return nil, api.ErrMissingCredentials
+	}
+
 	v := &PSA{
 		embed: &cc.embed,
 	}
diff --git a/vehicle/vw/identity.go b/vehicle/vw/identity.go
index c64191769..7d6d110ee 100644
--- a/vehicle/vw/identity.go
+++ b/vehicle/vw/identity.go
@@ -1,13 +1,13 @@
 package vw
 
 import (
-	"errors"
 	"fmt"
 	"net/http"
 	"net/http/cookiejar"
 	"net/url"
 	"strings"
 
+	"github.com/evcc-io/evcc/api"
 	"github.com/evcc-io/evcc/util"
 	"github.com/evcc-io/evcc/util/request"
 	"golang.org/x/net/publicsuffix"
@@ -57,7 +57,7 @@ func NewIdentity(log *util.Logger) *Identity {
 // UserLogin performs the identity.vwgroup.io login
 func (v *Identity) UserLogin(uri, user, password string) (url.Values, error) {
 	if user == "" || password == "" {
-		return nil, errors.New("missing credentials")
+		return nil, api.ErrMissingCredentials
 	}
 
 	// track cookies and don't follow redirects