What is a certificate of tax residence?
A certificate of tax residence is the document by which a country's tax authority certifies that an individual or a company is tax-resident in that country for a given tax year. It does not state how much you earn or how you are taxed: it simply certifies where you are resident for tax purposes.
In Spain this certificate has a very specific use: it is submitted to the Spanish Tax Agency (Agencia Tributaria / AEAT) to claim relief under a double-taxation treaty. Spain has treaties in force with many countries — including the United Kingdom and the United States — designed to prevent the same income (a dividend, interest, a pension, royalties, business profit) from being taxed in full by both States at once. To apply the treaty, the Spanish Tax Agency needs to know which country you are tax-resident in, and that is proved precisely by the certificate issued by the other State's tax authority.
Here we explain only what the document is and how it is translated. We do not give tax advice: for how your specific income is taxed, which rates or withholdings apply, or how to complete a return, consult a tax adviser or the Agencia Tributaria itself.
The two cases we translate most
United Kingdom — HMRC Certificate of Residence
HMRC (HM Revenue & Customs, the UK tax authority) issues the Certificate of Residence to those who are UK tax-resident and need to prove it to a foreign administration. When requested for Spain, the certificate can refer expressly to the treaty between Spain and the United Kingdom, which makes it easier for the Spanish Tax Agency to read. It is issued in English and obtained through HMRC's official channels (online request or the relevant form). How to request it is set out on gov.uk.
United States — IRS Form 6166 (with Form 8802)
For the United States, the document is the IRS Form 6166, an official letter on watermarked paper from the Internal Revenue Service certifying that a person or entity is a US tax resident for federal income-tax purposes. It is not downloaded directly: you must first file Form 8802 (Application for United States Residency Certification), and once the application is processed the IRS issues the Form 6166 for the year or years requested. It is issued in English. The IRS procedure and timelines are set out on irs.gov.
In both cases the source document is in English, so to submit it to the Spanish Tax Agency you need a sworn translation into Spanish.
Why a sworn translation into Spanish is needed
The Spanish administration works in Spanish and gives official value only to a translation produced by a sworn translator accredited by the MAEC (Spain's Ministry of Foreign Affairs, European Union and Cooperation). Your own translation, one from an agency without accreditation, or a machine version will not do for a procedure before the Spanish Tax Agency.
The sworn translation reproduces the certificate faithfully and gives it official standing: the sworn translator certifies, with their signature and accreditation number, that the Spanish version is complete and faithful to the English original. That is what allows an AEAT official to read and accept an HMRC or IRS document with the same assurances as if it were written in Spanish.
Apostille: not always required, confirm the requirement
With these certificates it pays to be precise. The Hague Apostille authenticates the signature on a foreign public document, but in practice certificates of tax residence are often submitted directly to claim treaty relief, and in many procedures the Spanish Tax Agency does not require an apostille on them.
That is not a universal rule: the requirement can depend on the specific procedure and office. So an apostille is not always required, but it is worth confirming whether it applies in your case before ordering the translation. Check with your adviser or directly with the Agencia Tributaria. And if it is required, obtain the apostille before commissioning the translation: that way we translate the certificate and the apostille stamp together, in a single document, and you avoid redoing the work.
What our sworn translation looks like
Our sworn translation of a certificate of tax residence:
- Reproduces the original in full — holder's details, country and tax identification, the tax year or period covered, and the double-taxation treaty reference when the HMRC or IRS certificate includes it.
- Translates all formal elements — the HMRC or IRS letterhead, references, stamps and signatures, and the apostille if the document carries one.
- Adds the sworn translator's official certification — signed declaration, MAEC accreditation number and qualified digital signature compliant with MAEC rules.
- Keeps the exact terminology of tax residence and of the treaty, so the Spanish Tax Agency reader can identify unambiguously what the document certifies.
Delivery format and timing
We deliver the translation as a PDF signed electronically with the sworn translator's qualified digital signature. This format has full validity before the Spanish Tax Agency and the entire Spanish administration. If your procedure requires a paper copy with handwritten signature and physical stamp, we send it by mail after the digital delivery.
The standard turnaround for a certificate of tax residence (usually a short document) is shown in the quoter before you confirm, together with the urgent options available. All turnaround times are calculated against the Spanish working calendar.
Common pitfalls to avoid
- Requesting the wrong year. Form 6166 and the Certificate of Residence relate to a specific tax year or period. Check that the year shown is the one your procedure needs before translating.
- Assuming an apostille is needed — or that it is not. Neither assumption is safe. Confirm the requirement with the Spanish Tax Agency or your adviser and, if needed, apostille before translating.
- Confusing the certificate with other tax documents. A tax return, a UK P60 or a US W-2 is not a certificate of tax residence. The valid document is the HMRC Certificate of Residence or the IRS Form 6166.
- A non-sworn translation. Only a translation by a MAEC-accredited sworn translator has official validity before the Spanish administration.
- Name discrepancies. If the name on the certificate does not exactly match your Spanish NIE or ID, we add a translator's note linking the two identities to prevent rejection.
Spanish bodies that accept our translation
- Spanish Tax Agency (AEAT) — application of double-taxation treaties, refunds and tax procedures.
- Regional tax offices and administrations (Delegaciones y Administraciones de Hacienda).
- Notaries and firms that need proof of tax residence in a transaction.
- Any Spanish body requiring official proof of foreign tax residence.
Related pages
- UK tax residence and Spain: the HMRC certificate — how to obtain the British Certificate of Residence and use it for the treaty.
- IRS Form 6166: US tax residency for Spain — Form 8802, Form 6166 and the Spain-US treaty.
- How to verify a MAEC-accredited sworn translator — why the sworn translation is the only one with official validity.