> ## Documentation Index
> Fetch the complete documentation index at: https://moengage-docs-limits-flows.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Why Does the "TopicDisallowed" Error Occur?

> Fix the TopicDisallowed error in iOS push caused by a mismatch between your app's Bundle Identifier and the one linked to the AuthKey (.p8) file.

## Problem

The "TopicDisallowed" error occurs when sending a push notification to a reachable user in iOS.

## Explanation

This error happens when the Bundle Identifier in the MoEngage push settings (associated with the AuthKey .p8 file) does not match the app's Bundle Identifier where the push notification is being tested.

## Example

If the app’s Bundle Identifier is com.xyz.moengage, but the Bundle Identifier linked with the AuthKey is com.abc.moengage, this error will occur.

## Solution

To resolve the "TopicDisallowed" error, the development team must address the abovementioned issue.