diff --git a/server/api/apierr/enums.go b/server/api/apierr/enums.go
index 6303670..1ff7709 100644
--- a/server/api/apierr/enums.go
+++ b/server/api/apierr/enums.go
@@ -26,6 +26,7 @@ const (
 	USR_MSG_ID_TOO_LONG    APIError = 1204
 	TIMESTAMP_OUT_OF_RANGE APIError = 1205
 	SENDERNAME_TOO_LONG    APIError = 1206
+	CHANNEL_TOO_LONG       APIError = 1207
 
 	USER_NOT_FOUND         APIError = 1301
 	CLIENT_NOT_FOUND       APIError = 1302
diff --git a/server/api/handler/api.go b/server/api/handler/api.go
index 489cd68..d4588fa 100644
--- a/server/api/handler/api.go
+++ b/server/api/handler/api.go
@@ -2,12 +2,14 @@ package handler
 
 import (
 	"blackforestbytes.com/simplecloudnotifier/api/apierr"
+	hl "blackforestbytes.com/simplecloudnotifier/api/apihighlight"
 	"blackforestbytes.com/simplecloudnotifier/common/ginresp"
 	"blackforestbytes.com/simplecloudnotifier/db"
 	"blackforestbytes.com/simplecloudnotifier/db/cursortoken"
 	"blackforestbytes.com/simplecloudnotifier/logic"
 	"blackforestbytes.com/simplecloudnotifier/models"
 	"database/sql"
+	"fmt"
 	"github.com/gin-gonic/gin"
 	"gogs.mikescher.com/BlackForestBytes/goext/langext"
 	"gogs.mikescher.com/BlackForestBytes/goext/mathext"
@@ -658,6 +660,18 @@ func (h APIHandler) CreateChannel(g *gin.Context) ginresp.HTTPResponse {
 		return ginresp.APIError(g, 500, apierr.DATABASE_ERROR, "Failed to query channel", err)
 	}
 
+	user, err := h.database.GetUser(ctx, u.UserID)
+	if err == sql.ErrNoRows {
+		return ginresp.SendAPIError(g, 400, apierr.USER_NOT_FOUND, hl.USER_ID, "User not found", nil)
+	}
+	if err != nil {
+		return ginresp.SendAPIError(g, 500, apierr.DATABASE_ERROR, hl.NONE, "Failed to query user", err)
+	}
+
+	if len(channelName) > user.MaxChannelNameLength() {
+		return ginresp.SendAPIError(g, 400, apierr.CHANNEL_TOO_LONG, hl.CHANNEL, fmt.Sprintf("Channel too long (max %d characters)", user.MaxChannelNameLength()), nil)
+	}
+
 	if channelExisting != nil {
 		return ginresp.APIError(g, 409, apierr.CHANNEL_ALREADY_EXISTS, "Channel with this name already exists", nil)
 	}
diff --git a/server/api/handler/message.go b/server/api/handler/message.go
index 68195a0..0e6f79a 100644
--- a/server/api/handler/message.go
+++ b/server/api/handler/message.go
@@ -178,7 +178,7 @@ func (h MessageHandler) sendMessageInternal(g *gin.Context, ctx *logic.AppContex
 		return ginresp.SendAPIError(g, 400, apierr.CONTENT_TOO_LONG, hl.CONTENT, fmt.Sprintf("Content too long (%d characters; max := %d characters)", len(*Content), user.MaxContentLength()), nil)
 	}
 	if len(channelName) > user.MaxChannelNameLength() {
-		return ginresp.SendAPIError(g, 400, apierr.CONTENT_TOO_LONG, hl.CHANNEL, fmt.Sprintf("Channel too long (max %d characters)", user.MaxChannelNameLength()), nil)
+		return ginresp.SendAPIError(g, 400, apierr.CHANNEL_TOO_LONG, hl.CHANNEL, fmt.Sprintf("Channel too long (max %d characters)", user.MaxChannelNameLength()), nil)
 	}
 	if SenderName != nil && len(*SenderName) > user.MaxSenderName() {
 		return ginresp.SendAPIError(g, 400, apierr.SENDERNAME_TOO_LONG, hl.SENDER_NAME, fmt.Sprintf("SenderName too long (max %d characters)", user.MaxSenderName()), nil)
diff --git a/server/test/send_test.go b/server/test/send_test.go
index 0248ccb..8e3771d 100644
--- a/server/test/send_test.go
+++ b/server/test/send_test.go
@@ -1188,11 +1188,43 @@ func TestSendToManualChannel(t *testing.T) {
 	}
 }
 
-//TODO post to channel
+func TestSendToTooLongChannel(t *testing.T) {
+	ws, stop := tt.StartSimpleWebserver(t)
+	defer stop()
 
-//TODO post to newly-created-channel
+	baseUrl := "http://127.0.0.1:" + ws.Port
 
-//TODO post to existing-channel
+	r0 := tt.RequestPost[gin.H](t, baseUrl, "/api/users", gin.H{
+		"agent_model":   "DUMMY_PHONE",
+		"agent_version": "4X",
+		"client_type":   "ANDROID",
+		"fcm_token":     "DUMMY_FCM",
+	})
+
+	uid := int(r0["user_id"].(float64))
+	sendtok := r0["send_key"].(string)
+
+	tt.RequestPost[tt.Void](t, baseUrl, "/", gin.H{
+		"user_key": sendtok,
+		"user_id":  uid,
+		"title":    "M3",
+		"channel":  "12345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890",
+	})
+
+	tt.RequestPost[tt.Void](t, baseUrl, "/", gin.H{
+		"user_key": sendtok,
+		"user_id":  uid,
+		"title":    "M3",
+		"channel":  "123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890",
+	})
+
+	tt.RequestPostShouldFail(t, baseUrl, "/", gin.H{
+		"user_key": sendtok,
+		"user_id":  uid,
+		"title":    "M3",
+		"channel":  "1234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901",
+	}, 400, apierr.CHANNEL_TOO_LONG)
+}
 
 //TODO post to foreign channel via send-key