How to Apostille a U.S. Certificate of Naturalization for Spain or Portugal (2026)
A step-by-step guide for naturalized U.S. citizens who need to use their Certificate of Naturalization in Spain or Portugal—including original vs. USCIS Certified True Copy, the federal apostille process, current State Department fees and timing, and what to do about translations.
If you became a U.S. citizen through naturalization and later need to present proof of that naturalization in Spain or Portugal, you may be asked for an apostilled Certificate of Naturalization.
This process is easy to get wrong because the certificate looks like a personal civil document, but it is not a state record like a birth or marriage certificate. It is issued by the federal government through U.S. Citizenship and Immigration Services (USCIS), part of the Department of Homeland Security.
First: Do You Actually Need to Apostille Your Naturalization Certificate?
Before sending an important citizenship document anywhere, confirm that the Spanish or Portuguese authority actually requires it.
For many standard immigration applications, your valid U.S. passport is the normal document used to establish identity and nationality. Current Spain Digital Nomad Visa instructions and current Portugal D8 residence-visa instructions list the passport as a core identity/travel document; an apostilled Certificate of Naturalization is not a routine item on those standard checklists.
If you are still choosing a relocation route, see our Spain relocation hub or Portugal relocation hub.
Why This Is a Federal Apostille, Not a State Apostille
The U.S. Department of State expressly identifies a Certificate of Naturalization issued by the Department of Homeland Security as an example of a federal document that may require an apostille for use in a Hague Convention country.
Spain and Portugal are both parties to the 1961 Hague Apostille Convention. A qualifying U.S. public document intended for use there therefore follows the apostille route rather than full diplomatic legalization.
Not:
Certificate of Naturalization → local notary → state Secretary of State.
Original vs. USCIS Certified True Copy: Which Should You Use?
This is where a lot of older online guidance is now misleading.
USCIS guidance explains how to obtain a Certified True Copy of a Certificate of Naturalization for use outside the U.S. government. Current U.S. Department of State apostille instructions, however, state that a federal document submitted for an apostille can be an original or certified copy, and the State Department specifically lists Certificates of Naturalization among federal documents covered by that guidance.
Option A: Submit the Original
Potential advantage: You avoid the additional USCIS certified-copy step.
Main concern: Your original proof of naturalization leaves your possession and travels through the authentication and return process.
If it is lost, stolen or damaged, replacement is handled through USCIS Form N-565.
Option B: USCIS Certified True Copy
Potential advantage: Your original remains in your possession after the USCIS appointment.
Main trade-off: You must complete the USCIS certified-copy process before requesting the federal apostille.
For applicants with sufficient time, this is often the more conservative document-handling route.
How to Get a USCIS Certified True Copy
USCIS refers to an authenticated photocopy of a Certificate of Naturalization as a Certified True Copy. It is handled by USCIS rather than by a private notary.
Request a USCIS appointment
Contact the USCIS Contact Center and ask for an appointment for a “Certified True Copy” of your Certificate of Naturalization.
Bring the original
USCIS guidance calls for the original Certificate of Naturalization or Certificate of Citizenship so the officer can examine it.
Bring a photocopy
Bring a clear photocopy that USCIS can compare with the original.
Bring photo identification
USCIS guidance identifies government photo ID such as a driver’s license, state ID or passport.
Receive the certified copy
If USCIS confirms your identity and citizenship status, a designated employee may certify the copy and return the supplied documents to you.
USCIS’s published guidance states that it does not certify these copies by mail or electronically.
Can You Send the Original to the State Department?
Under the U.S. Department of State’s current 2026 instructions, an eligible federal document may be an original or certified copy. The same guidance lists a Certificate of Naturalization as a federal document that may require an apostille.
So it is no longer accurate to categorically state that only a USCIS Certified True Copy can be apostilled. The practical issue is whether you are comfortable putting your original citizenship document into the process.
Step-by-Step: Federal Apostille Process
Confirm the destination country
Your request should identify the country where the document will be used: Spain or Portugal.
Complete Form DS-4194
This is the State Department’s Request for Authentication Services form.
Include the qualifying document
Submit the original or certified federal copy that satisfies the current Department of State requirements.
Pay the federal fee
The current State Department fee is $20 per document.
Choose the available submission route
The Office of Authentications currently offers mail processing and a limited walk-in drop-off/pick-up process depending on travel timing.
Current State Department Processing Times in 2026
| Your timing | Current federal option |
|---|---|
| Travel is 5 weeks or more away | Mail the request. The State Department currently says mailed requests are processed within about 5 weeks from receipt. |
| Travel is 2–3 weeks away | The current guidance permits walk-in drop-off and pickup, with published processing of about 7 business days. |
| Travel is 2 weeks or less | Appointments are limited to qualifying life-or-death emergency circumstances described by the State Department. |
Current Federal Addresses
U.S. Department of State
Office of Authentications
44132 Mercure Circle
PO Box 1206
Sterling, VA 20166-1206
Walk-in / physical office:
Office of Authentications
600 19th Street NW
Washington, DC 20006
Addresses, payment methods and public hours can change. Verify them on the official State Department page before shipping or traveling.
Do Not Notarize the Original Certificate
The current Department of State apostille instructions specifically warn applicants not to notarize the original federal document. The Department states that notarizing it will make the document invalid for this federal authentication process.
- A USCIS Certified True Copy is an official federal certification process.
- A private notary stamping a photocopy is not the same process.
- Notarizing the original Certificate of Naturalization is not the correct federal apostille route.
Spain: What Happens After the Apostille?
If the apostilled Certificate of Naturalization is being submitted in a Spanish immigration or administrative procedure, Spain’s immigration guidance generally requires foreign public documents to be properly apostilled/legalized where required and translated into Spanish, or where applicable a co-official language, through an accepted translation route.
Spain recognizes translations by an authorized sworn interpreter (traductor-intérprete jurado) and certain consular translation routes.
For the remote-work route, see the Spain Digital Nomad Visa guide. A naturalization certificate is not automatically a standard DNV requirement simply because the applicant is a naturalized U.S. citizen.
Portugal: What Happens After the Apostille?
Portugal’s translation rules depend on the procedure and receiving authority.
For Portuguese registry procedures, the Institute of Registries and Notaries states that foreign-language documents are generally accompanied by a certified Portuguese translation, although translation can sometimes be waived for documents in English, French or Spanish where the competent official understands that language.
If the certificate is being used in a visa or residence process, follow the current VFS, consular or AIMA instructions for that specific filing rather than assuming a registry exception applies.
See our Portugal D8 Digital Nomad Visa guide or Portugal D7 Visa guide.
Spain vs. Portugal: Quick Comparison
| Issue | Spain | Portugal |
|---|---|---|
| U.S. apostille authority | U.S. Department of State | U.S. Department of State |
| Why? | Certificate is a U.S. federal document | Certificate is a U.S. federal document |
| State apostille? | No, not for the USCIS certificate itself | No, not for the USCIS certificate itself |
| Translation | Spanish translation generally required where the document is submitted in an immigration/administrative filing | Certified Portuguese translation is generally the rule for registry use, with some possible English-language exceptions |
| Standard DNV/D8 identity document | Passport | Passport |
What If Your Certificate Is Lost, Stolen or Damaged?
USCIS Form N-565, Application for Replacement Naturalization/Citizenship Document, is used to request a replacement in situations including loss, theft, destruction or mutilation, as well as certain permitted corrections or updates.
Common Mistakes
- Sending the certificate to a state Secretary of State. It is a federal document.
- Notarizing the original. Current State Department guidance warns against this.
- Treating a notarized photocopy as a USCIS Certified True Copy.
- Using old processing-time information. Federal timelines change.
- Forgetting the country of use on DS-4194.
- Translating too early. Apostille first when the final apostille also needs to be covered by the translation.
- Apostilling a document you do not actually need. Many visa applicants only need their passport for nationality/identity evidence.
Certificate of Naturalization vs. FBI Background Check
| Document | Issued by | Purpose |
|---|---|---|
| Certificate of Naturalization | USCIS / Department of Homeland Security | Evidence of acquisition of U.S. citizenship through naturalization |
| FBI Identity History Summary | FBI / Department of Justice | Federal criminal-history information |
If your Spain case requires the FBI document, see our FBI Background Check & Apostille for Spain’s Digital Nomad Visa guide.
Our Recommended Sequence
Confirm the receiving authority wants the certificate
Ask whether a U.S. passport is sufficient or whether the Certificate of Naturalization itself must be submitted.
Choose original vs. Certified True Copy
Balance your deadline against the risk of sending the original certificate.
Prepare the federal apostille request
Complete DS-4194, identify Spain or Portugal as the country of use and follow the current State Department instructions.
Receive and preserve the apostilled packet
Do not separate or alter the apostille attachment.
Translate after apostille where required
Follow the Spanish or Portuguese authority’s current translation rules.
Need a U.S. Federal Document Prepared for Spain or Portugal?
We can coordinate the North American document layer—including federal and state apostilles, FBI records, civil documents, translation workflow and document sequencing—so your paperwork is prepared to current filing requirements.
For apostille and document-processing work, we coordinate through Tu Apostilla, our sister document-processing brand operated by Borderless Business LLC. Government processing times remain outside our control.
North American Document Concierge Consulate-Ready Pack Turnkey Relocation SupportFrequently Asked Questions
Who apostilles a U.S. Certificate of Naturalization?
Because the certificate is issued by USCIS, a federal agency within the Department of Homeland Security, its Hague Apostille is issued through the U.S. Department of State Office of Authentications rather than a state Secretary of State.
Can the original Certificate of Naturalization be apostilled in 2026?
Current U.S. Department of State guidance states that a qualifying federal document may be an original or certified copy and specifically lists Certificates of Naturalization among federal documents that may need an apostille. Applicants who prefer not to send the original can first obtain a USCIS Certified True Copy.
Can a notary certify my Certificate of Naturalization for apostille?
A private notarized photocopy is not the same as a USCIS Certified True Copy. USCIS has a specific certification process, and the State Department warns applicants not to notarize the original federal document.
How much does the federal apostille cost?
As of September 2026, the U.S. Department of State lists a $20 nonrefundable fee for each document submitted for authentication services. Verify the fee immediately before filing because government fees can change.
How long does a federal apostille take in 2026?
Current State Department guidance says mailed requests are processed within approximately five weeks from receipt. For travelers departing in two to three weeks, the current walk-in process lists approximately seven business days. Government processing times can change.
Do I need an apostilled Naturalization Certificate for Spain’s Digital Nomad Visa?
Not ordinarily as a standard identity document. Current DNV instructions use a valid passport as the core identity/travel document. Follow the checklist and any case-specific request from the authority handling your application.
Do I need one for Portugal’s D8 visa?
It is not a standard item on the current U.S. D8 checklist simply because the applicant is a naturalized U.S. citizen. The passport is the normal travel and identity document. Confirm any additional proof-of-citizenship request with the competent filing authority.
Should I translate the certificate before or after the apostille?
Where the receiving authority requires a translation of the complete legalized document, apostilling first and translating afterward lets the translation cover both the certificate and the attached apostille. Follow the specific receiving authority’s rules.
Official Sources
- U.S. Department of State — Prepare a Document for an Apostille Certificate
- U.S. Department of State — Request Authentication Services
- U.S. Department of State — Office of Authentications Contact and Addresses
- USCIS — Certified True Copy of a Certificate of Naturalization
- U.S. Department of State Foreign Affairs Manual — Certified True Copies
- USCIS — Form N-565
- HCCH — 1961 Apostille Convention Status Table
- Spain Ministry of Inclusion — Legalization and Translation of Foreign Documents
- Portugal IRN — Foreign Documents and Translation
Disclaimer: This article is provided for general informational purposes and does not constitute immigration, nationality, tax or legal advice. Document requirements vary by procedure and receiving authority and can change. DigitalNomadInSpain.org is not a law firm. Government processing times and acceptance decisions remain outside our control.