I was just very frustrated to discover that I couldn't enter my Canadian billing address in the UA app. Check out FT to see there's a solution. Further disappointed to find that the prices are all in USD rather than departure city, meaning a ~30% increase. But still 10% cheaper than I was seeing on the UA site/Google Flights/etc.
Seems UA is still not verifying billing addresses as I used the Houston address of my old employer and it seems to have gone through okay. Thanks go to FT once again
Now if only there was some way to get the US price but billed in CAD...