EOR payroll is payroll run by an employer of record as the legal employer of your hire: each month the EOR calculates gross-to-net under the hire's local law, withholds and files local taxes and social contributions, pays the employee in local currency and sends you one invoice covering salary, statutory employer costs and its fee. That is the mechanical picture. The part that surprises US buyers is what does not change: some US tax and social security rules attach to the person, not the payroll, and follow the hire regardless of who runs it.
The monthly mechanics
Because the EOR's local entity is the employer, everything a local employer must do runs under its registrations: income tax withholding, social contributions, payslips, statutory benefits and the filings each authority requires on its own calendar. You approve inputs such as salary changes and bonuses; the EOR executes. The invoice is the artefact worth studying. A clean one itemises gross salary, each employer-side statutory cost, benefits and the fee, in both local currency and your billing currency with the FX rate shown. An opaque one quotes a single blended number, which makes it impossible to check either the statutory arithmetic or the FX margin, and the FX margin is where quiet revenue lives.
Where US tax rules still reach
The IRS treats wages earned by nonresident aliens for services performed outside the United States as foreign source income, not subject to US federal income tax withholding or reporting, so a foreign national employed abroad by an EOR sits outside the US payroll system entirely. A US citizen is different: their worldwide income remains taxable to them personally wherever the payroll runs, and the mechanisms that manage this, such as the foreign earned income exclusion under IRC section 911, operate through their own filings. When a US person is employed abroad directly by a US company, withholding rules and Form 673 come into play; when the legal employer is the EOR's foreign entity, the employer-side picture changes but the individual's US obligations do not vanish. This page describes mechanisms, not advice; a US hire abroad should have a tax professional in the loop.
Social security: the double-coverage problem
Social security is where cross-border employment genuinely doubles up: a worker can owe contributions to two systems on the same earnings. The United States has totalization agreements with twenty-six countries to prevent exactly this. The default rule under the agreements is territorial, coverage where the work happens, with a detached-worker exception keeping temporary transfers of roughly five years or less in their home system, evidenced by a certificate of coverage. An EOR hire is usually a straightforward case: a local employee of a local entity, covered locally. The edge cases are relocating US staff who expect to stay in the US system; whether that is possible depends on the agreement and the employment structure, and it is a question to resolve before the contract is signed, not after.
What to verify with any EOR
Ask for a sample invoice for your actual country and salary before signing, and check that employer statutory costs are itemised against the local rates rather than blended. Ask which entity is the employer of record on the payslip, because that is who the tax authority pursues and who must act in a termination. Ask how the FX rate on the invoice is set and whether it is disclosed per line. And for any US-person hire, ask what the provider does and does not handle: most EORs run local payroll well and leave the employee's home-country obligations entirely to the employee, which is reasonable, but only if everyone knows that is the deal.
Questions people ask about eor payroll
Who withholds taxes in EOR payroll?
The EOR's local entity, as legal employer, withholds and files under the hire's local law. US federal withholding generally does not apply to a foreign national working abroad, whose wages are foreign source income under IRS rules.
Is a US citizen hired through a foreign EOR still on US payroll?
Not on yours. But their worldwide income remains taxable to them personally, managed through their own US filings and mechanisms like the section 911 exclusion. The EOR runs local payroll; it does not absorb the individual's US obligations.
Can an employee end up paying social security twice?
It can happen in cross-border arrangements, which is what US totalization agreements with twenty-six countries exist to prevent, using territorial coverage rules and certificates of coverage for temporary transfers. A standard EOR hire is usually covered locally and only locally.
What should the EOR invoice show?
Gross salary, each employer-side statutory cost itemised, benefits, the fee, and the FX rate applied. A single blended figure prevents you from checking the statutory arithmetic or the currency margin, and both deserve checking.