When you make a call on Facebook Messenger, it typically uses your internet connection, like Wi-Fi or mobile data. Since it doesn't use your cellular network for the call, it usually won't show up on your phone bill as a traditional phone call. Instead, it's treated as data usage [1].

Here are some key points to consider:

1. Messenger calls use internet data or Wi-Fi to make the call, so they are usually treated as data usage rather than a cellular call [1].
2. Messenger calls won't appear on your phone bill because they use the internet, not a phone line [2].
3. If you're using Messenger to make a call while connected to a mobile data network, then the call will count against your data allowance [2].
4. It's always a good idea to check with your specific mobile service provider to confirm how they handle Messenger calls and if any data charges may apply [1].

Learn more:

1. If I call a friend through Messenger, will the call show up on my ...
2. Do Facebook Messenger Calls Show Up On Phone Bill?
3. What Is WiFi Calling? Benefits and Best Providers - OpenPhone