Shadow payroll: meaning, how it works and when it is required

By the HRPricing editorial teamReviewed October 18, 2026How we research and score

A shadow payroll is a payroll run in a host country only to calculate, withhold and report tax on an employee who is still paid through their home-country payroll. The employee gets no money from it: it exists because the host country taxes work done on its soil, even when the salary comes from abroad.

A shadow payroll is a non-paying payroll an employer runs in a host country to report an assigned employee's compensation and to withhold and remit host-country taxes, while actual pay is delivered through the home-country payroll.

On this page
  1. How a shadow payroll works
  2. Example: a US employee seconded to the UK
  3. What "shadow tax" means
  4. When you need one, and the alternatives

How a shadow payroll works

  1. The home payroll keeps paying the employee as before.
  2. Each period, the shadow payroll takes the same compensation, plus host-taxable benefits such as housing or relocation allowances, and converts it into the host currency.
  3. It calculates host-country income tax and, if no exemption applies, social security.
  4. The employer files and pays those amounts to the host authority.
  5. The home payroll adjusts withholding so the employee is not taxed twice, often through a tax equalization policy.

Example: a US employee seconded to the UK

A US company sends an employee to London for two years on a salary equal to GBP 60,000. The UK generally taxes work done in the UK, so the company may need a UK shadow payroll to run income tax under PAYE; check HMRC's rules for employees seconded to the UK.

  • Social security without a certificate: UK employer National Insurance is 15% on earnings above GBP 5,000, so 15% x 55,000 = GBP 8,250 a year.
  • With a US certificate of coverage: the US and UK have a totalization agreement. A detached worker on an assignment expected to last 5 years or less stays in US Social Security only (SSA), so the company keeps paying US FICA instead: 7.65% from each side, covered in US payroll taxes.

UK employer figures are on the UK employer cost page. The EU version of the certificate is the A1 certificate.

What "shadow tax" means

Shadow tax usually means the host-country tax that the shadow payroll calculates and pays. In tax equalization arrangements, people also talk about a hypothetical tax: the amount the employee would have paid at home, which is withheld from them, while the employer pays the actual host-country tax.

When you need one, and the alternatives

You need a shadow payroll when an employee stays on the home payroll but works in a country that expects tax withholding on that work. You do not need one when you hire a local person through an employer of record, because the EOR runs a real local payroll. If you have your own entity abroad, a global payroll provider can run the host payroll: published prices start at $10 per employee a month at Playroll (minimums apply) and $29 at Remote (checked October 16, 2026). Compare models in EOR vs global payroll.

A related term, split payroll, pays part of the salary in each country. In a shadow payroll, all of the pay stays at home.

Frequently asked questions

What is shadow payroll?
A shadow payroll is a host-country payroll that pays the employee nothing but calculates, withholds and reports local tax on compensation that is paid through the home-country payroll.
What does shadow payroll mean for the employee?
The employee is paid once, from home. The shadow payroll makes sure host-country tax is withheld and reported, and the home payroll adjusts so the same income is not taxed twice.
What is shadow tax?
Shadow tax usually means the host-country tax computed and paid through a shadow payroll for an assigned employee. It is often paid by the employer under a tax equalization policy.
Does a shadow payroll cover social security?
Only if the host country's social security applies. A US employee sent abroad to a country with a US totalization agreement can stay in US Social Security for assignments expected to last 5 years or less with a certificate of coverage, per the SSA.
What is the difference between shadow payroll and split payroll?
In a shadow payroll all pay is delivered from the home country and the host payroll only handles tax. In a split payroll, part of the salary is actually paid through each country's payroll.
Sources (4)
  1. Social Security Administration: US international social security agreements (checked Oct 18, 2026)
  2. GOV.UK: Rates and thresholds for employers 2026 to 2027 (checked Oct 16, 2026)
  3. Playroll: Playroll homepage product cards (checked Oct 16, 2026)
  4. Remote: Remote pricing page (checked Oct 16, 2026)

This page is general information, not tax, legal or accounting advice. Rules and rates change, so check the official source linked above before you file or sign a contract. Read our disclaimer.