diff --git a/handlers/user.go b/handlers/user.go
index 1e0b8b4748..fe371b2603 100644
--- a/handlers/user.go
+++ b/handlers/user.go
@@ -1853,11 +1853,8 @@ func internUserNotificationsSubscribe(event, filter string, threshold float64, w
 		return false
 	}
 
-	isPkey := searchPubkeyExactRE.MatchString(filter)
-	filterLen := len(filter)
-
-	if filterLen != 0 && !isPkey {
-		errMsg := fmt.Errorf("error invalid pubkey characters or length")
+	if !isValidSubscriptionFilter(eventName, filter) {
+		errMsg := fmt.Errorf("error invalid filter, not pubkey or client")
 		errFields := map[string]interface{}{
 			"filter":     filter,
 			"filter_len": len(filter)}
@@ -1888,6 +1885,7 @@ func internUserNotificationsSubscribe(event, filter string, threshold float64, w
 		// rocketpool thresholds are free
 	}
 
+	filterLen := len(filter)
 	if filterLen == 0 && !strings.HasPrefix(string(eventName), "monitoring_") && !strings.HasPrefix(string(eventName), "rocketpool_") { // no filter = add all my watched validators
 		myValidators, err2 := db.GetTaggedValidators(filterWatchlist)
 		if err2 != nil {
@@ -2032,11 +2030,8 @@ func internUserNotificationsUnsubscribe(event, filter string, w http.ResponseWri
 		return false
 	}
 
-	isPkey := searchPubkeyExactRE.MatchString(filter)
-	filterLen := len(filter)
-
-	if filterLen != 0 && !isPkey {
-		errMsg := fmt.Errorf("error invalid pubkey characters or length")
+	if !isValidSubscriptionFilter(eventName, filter) {
+		errMsg := fmt.Errorf("error invalid filter, not pubkey or client")
 		errFields := map[string]interface{}{
 			"filter":     filter,
 			"filter_len": len(filter)}
@@ -2053,6 +2048,7 @@ func internUserNotificationsUnsubscribe(event, filter string, w http.ResponseWri
 		Network:        utils.GetNetwork(),
 	}
 
+	filterLen := len(filter)
 	if filterLen == 0 && !strings.HasPrefix(string(eventName), "monitoring_") && !strings.HasPrefix(string(eventName), "rocketpool_") { // no filter = add all my watched validators
 
 		myValidators, err2 := db.GetTaggedValidators(filterWatchlist)
@@ -2120,11 +2116,8 @@ func UserNotificationsUnsubscribe(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	isPkey := searchPubkeyExactRE.MatchString(filter)
-	filterLen := len(filter)
-
-	if filterLen != 0 && !isPkey {
-		errMsg := fmt.Errorf("error invalid pubkey characters or length")
+	if !isValidSubscriptionFilter(eventName, filter) {
+		errMsg := fmt.Errorf("error invalid filter, not pubkey or client")
 		errFields := map[string]interface{}{
 			"filter":     filter,
 			"filter_len": len(filter)}
@@ -2134,6 +2127,7 @@ func UserNotificationsUnsubscribe(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	filterLen := len(filter)
 	if filterLen == 0 && !types.IsUserIndexed(eventName) { // no filter = add all my watched validators
 
 		filter := db.WatchlistFilter{
@@ -2182,6 +2176,27 @@ func UserNotificationsUnsubscribe(w http.ResponseWriter, r *http.Request) {
 	OKResponse(w, r)
 }
 
+func isValidSubscriptionFilter(eventName types.EventName, filter string) bool {
+	ethClients := []string{"geth", "nethermind", "besu", "erigon", "teku", "prysm", "nimbus", "lighthouse", "lodestar", "rocketpool", "mev-boost"}
+
+	isPkey := searchPubkeyExactRE.MatchString(filter)
+
+	isClientName := false
+	for _, str := range ethClients {
+		if str == filter {
+			isClientName = true
+			break
+		}
+	}
+
+	isClient := false
+	if eventName == types.EthClientUpdateEventName && isClientName {
+		isClient = true
+	}
+
+	return len(filter) == 0 || isPkey || isClient
+}
+
 func UserNotificationsUnsubscribeByHash(w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("Content-Type", "text/html")
 	q := r.URL.Query()