[phonebanshee]

They want to be an employee of a company in California, while living and working in Canada. This sounds like it's going to be complicated, and a blanket answer of "you don't pay US taxes" seems unlikely to be correct. They're also going to face issues like on day 1 when they walk into the office and they're going to have to go through the whole I-9 thing (https://www.uscis.gov/i-9-central) - waving hands and saying I'm going to live in Canada seems like it's not a solution.

[dboreham]

They can't be an employee of a US corporation (as in, a person who gets a W-2, etc).

What they can do is either a) have the US employer set up a Canadian subsidiary that handles their payroll or b) set up their own Canadian legal entity (corporation, sole trader??) and execute a services contract between the two companies. Then they can pay themselves under Canadian rules out of that company, or do whatever plumbers do in Canada -- sole trader or whatnot.

ianal, nor Canadian.