diff --git a/server/routers/olm/error.ts b/server/routers/olm/error.ts
index 978c1a1a..c02c571c 100644
--- a/server/routers/olm/error.ts
+++ b/server/routers/olm/error.ts
@@ -5,6 +5,7 @@ export const OlmErrorCodes = {
     CLIENT_ID_NOT_FOUND: "CLIENT_ID_NOT_FOUND",
     CLIENT_NOT_FOUND: "CLIENT_NOT_FOUND",
     CLIENT_BLOCKED: "CLIENT_BLOCKED",
+    CLIENT_PENDING: "CLIENT_PENDING",
     ORG_NOT_FOUND: "ORG_NOT_FOUND",
     USER_ID_NOT_FOUND: "USER_ID_NOT_FOUND",
     INVALID_USER_SESSION: "INVALID_USER_SESSION",
diff --git a/server/routers/olm/handleOlmRegisterMessage.ts b/server/routers/olm/handleOlmRegisterMessage.ts
index 0c69ce8d..242fe345 100644
--- a/server/routers/olm/handleOlmRegisterMessage.ts
+++ b/server/routers/olm/handleOlmRegisterMessage.ts
@@ -90,6 +90,18 @@ export const handleOlmRegisterMessage: MessageHandler = async (context) => {
         return;
     }
 
+    if (client.approvalState == "pending") {
+        logger.debug(
+            `Client ${client.clientId} approval is pending. Ignoring register.`
+        );
+        sendOlmError(
+            OlmErrorCodes.CLIENT_PENDING,
+            "Client approval is pending",
+            olm.olmId
+        );
+        return;
+    }
+
     const [org] = await db
         .select()
         .from(orgs)