Living in Canada, working in the US

Good day,
You have undoubtedly been asked this question on numerous occasions.  My wife works in the United States, but we reside in Canada.  She recently has become a permanent resident in Canada, but has yet to receive a SIN.  We know she must file a tax return in Canada (under the deemed resident statute) however since she does not earn an income in Canada, and her salary is in US$ what amounts do we fill on her Canadian income return??  Can my salary (which is less than hers) somehow be applied on her return as well??  Does she as well get a 2 month extension on her US return date in order to file her Canadian return??
Thank you for your time a nd consideration.
Best regards,
> david ingram replies:
> If you are commuting to work in the USA, you must file a US tax return first and then refile the same amounts in Canada.  You would convert the US earnings to Canadian dollars and put the amount on lines 104 (not 130) and 433 (schedule 1) of your Canadian T1 return.  You then claim the Federal tax, State tax, FICA (social security) and Medicare  paid to the US as a foreign tax credit on line 431 of your Canadian return.  If there is anything left over you can apply it as a provincial foreign tax credit on line 48 of provincial form 428 after filling in form T2036.  (If you are in Quebec, You would use Quebec form TP-772-V to calculate and put the credit on line 409 of your TP1.
> She should file US form 4868 to extend her time to file the US return which is due at midnight April 17th otherwise and, of course, her Canadian in due April 30th.
> You know where we are if you need help.
> She will get a little more by going to and reading the US/Canada Taxation section in the second box down on the right hand side.