I made a call using the Facetime app but it used the phone and I ended up paying a hefty bill.

Quite simple.

You are NOT looking at the FaceTime app here. You are looking at Contacts.

> If you press the pointed button on my phone (iphone 13 pro Max), the call definitely goes to Cellular/Mobile here in the UK. As proof, the circled bit says the last call was made using the SIM card.

If your default calling app is set to Phone then, yes, clicking the Call button will initiate a phone call, using whatever mobile provider your phone is connected to.

If you want to make a FaceTime call, click either the Camera or Phone Handset icons alongside the FaceTime label.

Both of these options will initiate a call using either FaceTime Audio or FaceTime Video.

Now, if you're not on a WiFi network, FaceTime will use the cellular data plan associated with your SIM - so, technically, it will 'use your SIM', but its use counts towards data usage, not phone call minutes.

I think you're misunderstanding this setting.

The phone has one, and only one, setting for the 'default application to use for calls".

This default can be the Phone app, FaceTime, or any other compatible app installed on your device.

What ay be confusing you is that there are multiple places to set this preference setting - you can set it in the Phone settings, or in FaceTime settings, but it's the same thing.

It's only really relevant when initiating a call from another app, though, such as in Contacts. The Phone app will always use the cellular service (or WiFi if your provider supports WiFi calling), and FaceTime will always use FaceTime (over WiFi or cellular, based on your preference) if you initiate calls from within those apps.

> I don’t see the answer to the question after repeatedly saying only post if you know the answer!!

I think you're missing my point. Maybe I can try rewording it.

The FaceTime App CAN NOT AND WILL NOT make phone calls.

If you initiate a call using the FaceTime app it will either use FaceTime Audio, or FaceTime Video to other FaceTime users. Both options require a data connection (either WiFi or cellular).

If you enter a phone number that is not associated with a FaceTime user, FaceTime will offer to send that user a text message inviting them to FaceTime.

Under no circumstance will FaceTime initiate a phone call to a regular phone number.

I maintain that there is ONE AND ONLY ONE 'default calling' option in preferences. There is NOT a separate 'default calling' option for Phone and FaceTime. They are one and the same - your default is EITHER Phone OR it is FaceTime.

Therefore, respectfully, I DID read your post and I attempted to guide you based on a perceived misconception. I'm sorry if you can't accept that.