Travel to Canada

T-Mobile's coverage in Canada is mostly provided by the Bell/Telus network.  It is fairly decent coverage depending on where you are going in Canada.  If you are heading up to one of the territories, then service might be limited or non-existent due to it just being incredibly rural.  Major cities like Toronto  Montreal, Quebec City, Vancouver, Edmonton, Calgary, and Winnepeg will all have excellent coverage. 

Make sure your plan includes Canada and understand what it comes with.  The Magenta Plan I have as an example, includes calling and texting to and from Canada at no extra cost with up to 5GB of high speed data.  Exceeding that drops me down to almost unusable slow speeds that would not be good enough to use any sort of Map app for directions. 

Give Customer Care a call at 611 or reach out to T-Mobile via DM on Facebook or Twitter.  Have them make sure that international roaming is enabled on your account, have them confirm your plan includes Canada for calling, texting, and roing, and see what data add-ons are available for your plan if you intend on using more data that what your plan might provide.