International global payroll means paying employees compliantly in more than one country: local-currency net pay, local tax withholding, local social contributions and local filings, every cycle, in every jurisdiction where someone sits. No provider waves that complexity away; the choice is between models that consolidate it differently. Underneath every model the same two compliance layers repeat per country: income tax withholding under local law, and social security, where cross-border assignments add a second question of which country's system the worker even belongs to.
The three delivery models
The aggregator model stitches together in-country payroll providers under one contract and one reporting layer; quality then depends on the weakest local partner, but coverage is broad. The single-platform model runs payroll on the provider's own engine in each covered country, which gives consistent data and processing but a shorter country list. The employer-of-record model is different in kind: where you have no entity, the EOR is the legal employer and payroll is simply part of its service, so it solves registration as well as processing. Most multi-country employers end up hybrid, running owned entities on an aggregator or platform and entity-less countries through an EOR, and the practical selection questions are which countries are served natively, who answers when a local filing is wrong, and how data leaves the system.
Social security across borders: totalization and the detached worker rule
When an employee works in a different country from the employer, both countries' social security laws can claim the same wages. The United States addresses this through bilateral totalization agreements with 28 countries. The Social Security Administration describes the general rule as territorial, coverage in the country where the person works, with a detached worker exception: someone temporarily transferred by the same employer, on an assignment expected to last five years or less, stays in the home system. The exemption is documented by a certificate of coverage obtained from the country whose system continues to apply, usually requested by the employer. Payroll has to reflect that determination every month, which is why assignment planning and payroll cannot be run in separate silos.
The US wrinkle: withholding for citizens working abroad
US employers keep federal obligations for US-citizen and resident employees working overseas. The IRS's guidance on persons employed abroad by a US person sets the default: wages for services performed outside the United States are generally still subject to US income tax withholding, with exceptions, including where the employer reasonably believes the pay will be excluded under the foreign earned income rules, in which case the employee provides Form 673, or where the law of the foreign country requires income tax withholding on the same wages. Nonresident-alien employees working entirely outside the US are the mirror case: their wages are foreign-source and not subject to US withholding. A global payroll setup that treats every country file as purely local misses this home-country layer.
Questions people ask about international global payroll
What is the difference between international payroll and an EOR?
International payroll processes pay for employees your own entities employ; you must already be registered as an employer in each country. An EOR is the legal employer where you have no entity, and running payroll is one component of that service. Many companies use both at once for different countries.
Can one provider really pay people in every country?
No provider runs its own engine everywhere. Broad coverage is delivered either through networks of in-country partners or through mixed models, so the questions that matter are which countries are served natively, how partner quality is controlled, and who is accountable for a wrong local filing.
What is a certificate of coverage?
A document proving which country's social security system covers a cross-border worker under a totalization agreement, so the other country's contributions are not owed on the same wages. It is obtained from the country whose system continues to apply, typically at the employer's request.
Does a US company still withhold US tax for a US citizen working abroad?
Generally yes, unless an exception applies, such as the employee claiming the foreign earned income exclusion on Form 673 or the foreign country's law requiring its own withholding on the same wages. The determination is per-employee and belongs inside the payroll process, not after it.