Q: When you FaceTime internationally, do you use the international calling codes or just the local code e.g. for UK, do you put 011 44 for England before the number, +44, or leave it out? I am having no success so far.

– Sheila

A: The “011” dialling code is actually only used when placing calls from traditional landlines. While some mobile carriers will accept it for backward compatibility, the proper way to dial an International number on a mobile phone is to prefix the country code with a “+” sign, so to place a call to the U.K., “+44” would be the correct prefix. Conversely, for somebody outside of North America to place a call to Canada or the U.S., the prefix would be “+1” followed by the standard 10-digit North American phone number.

FaceTime follows this same dialling convention. However, it’s important to keep in mind that FaceTime is actually a completely separate network from your mobile carrier, although it can use 3G/LTE data, if you’re using a supported device and not on a Wi-Fi network. As a result, the phone numbers used by FaceTime are really just “addresses” on the FaceTime network that match users’ cellular phone numbers.

FaceTime can also be configured to “call” people using e-mail addresses rather than phone numbers. In fact, this is required for non-iPhone users to use FaceTime on an iPad, iPod touch, or Mac, since these devices do not have phone numbers associated with them. You can configure FaceTime on an iPhone to also use an e-mail address simply by going to Settings, FaceTime, selecting the option to “Use your Apple ID for FaceTime” and then signing in with your Apple ID and password. This can be your iTunes Store or iCloud account, or if you prefer you can setup an entirely new Apple ID for this process.

You can “dial” someone else’s e-mail address to place a FaceTime call simply by selecting the contact from the address book, tapping the “FaceTime” button and then selecting their e-mail address rather than their phone number.

If you’re having issues placing FaceTime calls to a phone number, having the other person setup an e-mail address may help, since this bypasses the requirement to use a phone number. That said, there are many reasons why a FaceTime call can fail, and often it has nothing to do with the phone number or address that you’re using, but rather other issues related to network configuration and Internet connectivity. For more information on setting up FaceTime and troubleshooting problems with it, check out our Guide to FaceTime + iMessage: Setup, Use, and Troubleshooting.