An assignment letter spells out what happens when you send an employee to work in another country. It covers duration, compensation adjustments, housing or relocation allowances, tax responsibilities, and repatriation terms. Without one, you’re inviting disputes over who pays for what when the assignment ends.
Most EOR arrangements don’t involve traditional assignment letters because the employee is hired locally from the start. Assignment letters matter when you have an existing employee in one country and need them working in another — a secondment or intra-company transfer. The EOR in the host country may still need to issue a local employment contract alongside your assignment letter.
The tax implications are where assignment letters get complicated. An employee on a 6-month assignment to France triggers French tax obligations after 183 days. The assignment letter should specify whether the company grosses up taxes, applies tax equalization, or leaves the employee to sort it out. Most companies above 500 employees use tax equalization. Smaller companies often don’t realize they need to address this until the employee gets a surprise tax bill.
A well-drafted assignment letter covers five things: assignment duration with clear start and end dates, compensation structure including any cost-of-living adjustments or hardship allowances, benefits continuation or replacement during the assignment, tax treatment specifying which party bears the incremental tax cost, and repatriation terms including what role the employee returns to. Skip any of these and you’ll hear about it from the employee — or their lawyer.
The ILO’s guidelines on migrant workers recommend that assignment terms be documented before the worker relocates, not after. That recommendation exists because companies routinely delay formalizing assignment terms, then face disputes when the employee’s expectations don’t match the company’s intentions.
Why It Matters for EOR
If you’re using an EOR to manage an international assignment rather than a fresh local hire, the assignment letter and the local employment contract must work together without contradicting each other. The assignment letter governs the relationship between you and your employee. The local employment contract governs the relationship between the EOR and the employee in the host country. Conflicts between the two — on notice periods, severance, or benefits — create legal exposure in both jurisdictions.
Before structuring a cross-border assignment, compare EOR vs. entity setup to determine whether an EOR-managed assignment or a direct entity transfer is the cleaner path. For assignments under 12 months, EOR is almost always simpler. For longer assignments, your own entity may give you more control over assignment terms and cost.
For practical use of this concept, see EOR vs PEO explained and country hiring guides.
Sources
Published list prices, country counts, and entity models link to official provider pages (June 2026). eorHQ scores use our 6-dimension methodology.
Related Decision Pages
- EOR vs. entity: choosing the right structure for international assignments — Assignment letters are more common with entity-based transfers, but EOR arrangements sometimes require them alongside local contracts.
- Hiring in the United Kingdom: assignment terms and tax implications — The UK’s 183-day tax rule and PAYE system create specific obligations that assignment letters need to address.
- EOR comparisons
- Read Deel review
- EOR vs PEO explained
Worked Example
A mid-market company evaluating global hiring encounters Assignment Letter when comparing EOR quotes. The practical test: ask any provider to show how assignment letter affects total year-one cost in your top hiring country — not just the headline monthly fee.
Use the employee cost calculator and how to choose an EOR to pressure-test provider claims against your hiring plan.
When Assignment Letter Matters in EOR Decisions
Assignment Letter becomes decisive when you are comparing finalists on compliance risk, not feature checklists. Three triggers: (1) your first hire in a regulated market like Germany or Brazil, (2) a compliance audit or investor diligence request, and (3) scaling past 10 employees in one country where entity economics start competing with EOR fees.
See EOR vs entity, compliance risks, and provider reviews for how this term shows up in real buying decisions.
Common mistakes buyers make with Assignment Letter
Teams often treat Assignment Letter as a checkbox on a vendor slide deck instead of a contractual and operational reality. The expensive mistakes: assuming your company retains employer liability when the EOR is legal employer, skipping country-specific documentation requirements, and comparing providers on monthly fee without modeling statutory pass-through costs.
Another failure mode is mixing models — using contractors where assignment letter employment is required, or opening an entity in one country while using EOR elsewhere without a coherent global employment policy.
How EOR providers handle Assignment Letter
Most tier-one providers (Deel, Remote, Multiplier) document assignment letter in onboarding workflows and contract packs, but execution quality varies by country. Ask for a sample workflow in your top hiring market, not a global marketing PDF.
A formal document outlining the terms, compensation, and duration of an employee’s international work assignment and how it relates to EOR hiring.
Frequently Asked Questions
Does Assignment Letter affect total employment cost?
Yes — often more than the platform fee. Model all-in cost with the employee cost calculator and EOR cost guide.
Is Assignment Letter the same in every country?
No. Local labor law governs how assignment letter works in practice. Pair this definition with the relevant country hiring guide before you sign.
Where does Assignment Letter show up in provider reviews?
We score compliance and entity-model execution in every EOR review — the dimensions where assignment letter matters most operationally.
Common mistakes buyers make with Assignment Letter
Teams often treat Assignment Letter as a checkbox on a vendor slide deck instead of a contractual and operational reality. The expensive mistakes: assuming your company retains employer liability when the EOR is legal employer, skipping country-specific documentation requirements, and comparing providers on monthly fee without modeling statutory pass-through costs.
Another failure mode is mixing models — using contractors where assignment letter employment is required, or opening an entity in one country while using EOR elsewhere without a coherent global employment policy.
How EOR providers handle Assignment Letter
Most tier-one providers (Deel, Remote, Multiplier) document assignment letter in onboarding workflows and contract packs, but execution quality varies by country. Ask for a sample workflow in your top hiring market, not a global marketing PDF.
A formal document outlining the terms, compensation, and duration of an employee’s international work assignment and how it relates to EOR hiring.
Frequently Asked Questions
Does Assignment Letter affect total employment cost?
Yes — often more than the platform fee. Model all-in cost with the employee cost calculator and EOR cost guide.
Is Assignment Letter the same in every country?
No. Local labor law governs how assignment letter works in practice. Pair this definition with the relevant country hiring guide before you sign.
Where does Assignment Letter show up in provider reviews?
We score compliance and entity-model execution in every EOR review — the dimensions where assignment letter matters most operationally.
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