Thank you @benoit.associes1
My Client lives in Windsor Ontario and commute to Detroit for work.
There are state taxes im Michigan.
If he is a US Person, he’s on hook to declare his Canadian earnings on the 1040, not 1040NR. If he’s a non resident alien with green card not allowing to live in the US, he’s not a US person and there are no personal deductions on the tax return which means he will have paid tax regardles of the amount earne and he can claim the foreign tax credit in Canada.