Hi,

What is the tax withholding/rules for a Canadian citizen/resident who will be temporarily working at a US firm for the summer?

I am not familiar with the new amendments to the Canadian/US tax treaty

Thank you

If you are working INSIDE the United States, you must withhold at SINGLE rate with either ONE or ZERO exemption.

If you are working OUTSIDE of the United States, you have NO U.S. income tax liability and should be exempt from withholding on U.S. taxes.

Whether you are liable for U.S. FICA taxes depends on the visa you are working under.