Can I use my iPhone in Montreal?

No, you can’t. And if you use data, you’ll get a $500 phone bill like I did.

It’s super expensive.

No, you’ll get HUGE roaming charges.

I suggest you only use data when you’re on a Wi-Fi connection or get a prepaid SIM card with data if you really need it. (make sure your iPhone is unlocked though)

Awesome, thanks!

@seekingwolf

Make sure you turn on Airplane Mode! It’s in Settings and turns off all the cell phone radios, which connect to AT&T and charge you $. (You can have wifi on)

Even if you have airplane mode off, your phone will connect to the network, and that causes roaming charges!!

Turn it off when you get back in the states.

If it is unlocked one means you can use it in Canada or else you need to unlock your Iphone with current network provider. To unlock your Iphone you can use Remote unlocking method.If you are intersted in this method of unlocking visit http://www.theunlockspot.com/apple-iphone/rs16wp9/ . After unlocking you can use it in Canada.