Moving from US to Canada

You cannot use a Canadian number with AT&T.   AT&T prepaid 8 gig or higher plan roams at no extra charge, but all At&t plans roam in Rogers, which may or may not be desirable.

@adidaskid808  is in Canada, but uses local service wherever he travels.  

@Luv2travelaa @lizdance40 

My first question is where in CANADA you're moving to??

You're MOVING to Canada for the next one or two years,that mean you're new to the country and you do not have any credit history in here?? You may not be able to apply for postpaid service,prepaid are your only choice.

As @lizdance40 reply,you cannot use a Canadian number with AT&T,but are you using postpaid with AT&T ??

Cell phone voice call, SMS and data are expensive in here!!!For prepaid,in 2020 October,price will go up to $0.60 Canadian per min and per SMS. Data remain the same at Can$1 for 10 MB!! (exchange rate for Canadian $ to US$ is between 25% to 30% different) .

Do you have a dual sim phone??
Do you have an unlocked phone??

You may need to reply the above questions before I can help you more.

@adidaskid808  thank you!  You can give much better info! 

Thank you for the info.  Here’s some additional info.

I have dual citizenship (US/Canada) and have some credit history in Canada (since I lived there 15 years ago).  I’m currently using an iPhone 8 Plus but am considering upgrading it to another iPhone.  I will pay for the new phone in full prior to leaving the US so I can switch to another Canadian carrier if needed.  I’m on an Elite plan that allows me to roam freely in Canada.  I’ll be living close to Guelph, Ontario.  

Credit history in Canada (since I lived there 15 years ago). 
I don't know if you still got any history left ,it is already 15 years. If you still have a Canadian Credit card,it may help.

Pay for the new phone in full prior to leaving the USA.
Get it unlocked!!! Although AT&T toll free numbers & 611 are working free in Canada,but it maybe a long hold !!

Living close to Guelph, Ontario
Don't know if you are a heavy user on cell phone and data,to me both Rogers and Bell works well around the cities and surrounding.Both network are bad on billings LOL !!

By the way,
, @sandblaster 
do say something you need to look out for .

I have 4 phones on my Att unlimited plan. One of the phone users is moving to Vancouver,bc Canada. What can I do to keep coverage on the phone and avoid additional charges. I expect the move to be 1-2 years. Would like to keep same phone number.

See https://www.att.com/international/canada-roaming/ for AT&T's information regarding this.  There used to be a caveat about the length of time you could stay in Canada without coming back into the United States without having your plan canceled.  However, I cannot find any such statement in the terms & conditions now, or in the Canada & Mexico descriptions.

@Lisamagann 

Postpaid users can continue to use their AT&T service planned in Canada, and Mexico, Puerto Rico and the US Virgin Islands. Roaming is free and all of these locations.

  There are no roaming charges, or long distance charges for calls or texts in and between the US and Canada.  

    The user can continue to use their US phone number in Canada and the US plan in Canada just as they did inside the USA. 

Hi all, This post is old, I can give you all some update on AT&Tprepaid and post paid use in Canada. 

For postpaid, as long as your bill are paid up to days, you can use your allowance as you are in USA. But keeping the number to change to a Canadian network maybe still not possible.

For prepaid, AT&T are not roaming only on Roger's network now, it also work on Bell and Telus, I switched my plan once when I travel to USA, I cannot switch back to the $2 daily plan.

Also, Huawei and ZTE phones do not work with AT&T Sim card, no matter roaming or in Mainland USA.

Hope this update helps.