yes, Thats what I mean by payroll taxes, If I work remote than it means I am employed by US employer in Canada not in US, which requires them to deduct taxes and remit to CRA.
Since you are a Canadian resident you pay to CRA taxes on your global income, you can claim taxes paid to US as credit, thats what I mean by Foreign tax credit(FTC). When working remote completely from Canada, CRA is taking issue with claiming FTC on taxes paid to IRS. They are saying, Tax returns should be first filed in Canada and then take Tax credit on US side, thereby paying taxes to Canada and asking for a refund from IRS. This can result to cash flow issue as you have to pay CRA even though your taxes might have been withheld by your employer and paid to IRS.
From what I can see traveling few days a month is safest approach. thereby you can easily claim FTC and everyone is happy.
@harirajmohan If I can't get a refund from IRS on my Social Security, can I claim it as Foreign Tax Credit?