This guide explains how to obtain a UK Apostille for a Certificate of Naturalisation / Certificate of Registration for Spain Dual Citizenship, including UK solicitor certification (remote available), Apostille requirements, and Spain-specific rules for dual citizenship.
Since Brexit, Spanish authorities have applied stricter checks to UK nationality documents. As a result, a British passport alone is not enough. Instead, Spain requires a properly certified and apostilled UK Certificate of Naturalisation or Certificate of Registration.
Preparing the document correctly from the start helps you avoid rejection, delay, or repeated submissions.
Is Dual Citizenship with Spain Allowed?
Spain does not generally recognise dual citizenship with the United Kingdom.
There is no bilateral dual-nationality agreement between the two countries.
However, Spanish nationality can be retained if Spanish law is followed and the correct declaration is made. This issue mainly affects Spanish nationals who later acquire British nationality.
Spanish Nationals Acquiring British Nationality
Use It or Lose It
Under Article 24 of the Spanish Civil Code, Spanish nationality may be lost if certain conditions apply.
For example, nationality may be lost if a person:
- resides abroad and does not use Spanish nationality for three years, or
- voluntarily acquires another nationality, including British nationality, without declaring conservation, or
- was born abroad to Spanish parents who were also born abroad and does not retain nationality at age 18.
Because Spain and the UK have no dual-citizenship treaty, Spanish nationals who naturalise as British must actively declare conservation of Spanish nationality.
Otherwise, difficulties may arise later. These often appear during passport renewal, consular registration, inheritance matters, or nationality confirmation.
How to Retain Spanish Nationality After Becoming British
To retain Spanish nationality, you must submit documents to the Spanish Consulate and then attend a consular appointment.
In most cases, the Consulate requires:
- Declaration of Conservation of Nationality (official form)
- Photocopy of Spanish passport and Spanish DNI (originals shown at the appointment)
- Photocopy of British passport (original shown at the appointment)
- Certified True Copy of the UK Certificate of Naturalisation or Certificate of Registration, with Apostille
- Photocopy of birth certificate
After review, the Consulate will arrange an appointment. At that appointment, you sign the Act of Conservation of Nationality.
Once the Consulate confirms the declaration, Spanish nationality is retained.
Why Spain Requires a UK Apostille for a Certificate of Naturalisation
Spanish authorities do not accept informal or incomplete documents. For instance, they usually reject:
- simple photocopies or scans,
- solicitor statements based only on printouts,
- uncertified copies, or
- Apostilles applied to the wrong document format.
Instead, Spain requires a clear legal chain.
First, a UK solicitor or notary prepares a certified true copy of the Certificate of Naturalisation or Registration.
Next, the UK government authenticates that certification through an Apostille issued by the Foreign, Commonwealth & Development Office.
This process is why a UK Apostille for a Certificate of Naturalisation is mandatory for Spain.
A British passport alone does not meet this requirement, because it does not show how or when British nationality was acquired.
What Is a UK Certificate of Naturalisation?
A UK Certificate of Naturalisation is the official document confirming that a person became a British citizen through naturalisation.
People commonly use this certificate for:
- nationality and immigration matters,
- right of abode,
- British passport applications,
- overseas legal and administrative procedures, and
- Spanish dual-citizenship registration.
Certificate of Registration: Not the Same Document
A Certificate of Registration applies when British citizenship is acquired by registration rather than naturalisation.
This often affects:
- children of British citizens, or
- individuals entitled through British Overseas Territories or similar routes.
For Spain, Certificates of Registration usually require the same UK Apostille and solicitor certification process.
UK Solicitor Certification and Apostille
Remote Certification Available
For Spain, UK nationality certificates normally require:
- a certified true copy prepared by a UK solicitor or notary, and
- a UK Apostille for the Certificate of Naturalisation or Certificate of Registration.
In many cases, UK solicitor certification can be completed remotely, for example by video conference, subject to the solicitor’s professional requirements.
As a result, clients outside the UK can often complete the process without attending a physical office.
Benefits of Holding Spanish Dual Citizenship
Spanish dual citizenship provides practical advantages.
For example, it allows:
- freedom of movement across the EU and the Schengen Area,
- the right to live and work in all EU member states,
- access to public healthcare, education, and services in Spain,
- strong passport protection under Spanish law, and
- long-term certainty for family, property, and residency planning.
How to Obtain a UK Certificate of Naturalisation (Overview)
Applicants for naturalisation usually must meet several conditions.
These typically include:
- lawful residence in the UK,
- indefinite leave to remain or settled status,
- compliance with residence and absence limits,
- passing the Life in the UK Test, and
- meeting good-character and language requirements.
Once issued, the certificate can be prepared for Spain through UK solicitor certification and Apostille.
Lost Your Certificate of Naturalisation?
If you lose your certificate, you can request a replacement.
The process usually involves:
- submitting Form NC to the UK authorities,
- paying the applicable Home Office fee, and
- providing evidence of any name changes, if relevant.
After reissue, the replacement certificate can receive a UK Apostille for Spain.
How Ginkgo Advisory Can Help
Ginkgo Advisory supports clients who need a UK Apostille for a Certificate of Naturalisation for Spain or a UK Apostille for a Certificate of Registration for Spain.
We help by:
- reviewing your UK Certificate of Naturalisation or Certificate of Registration,
- arranging UK solicitor certification, including remote certification by video conference where appropriate,
- coordinating the UK Apostille issued by the Foreign, Commonwealth & Development Office (FCDO), and
- returning the completed documents securely for submission to the Spanish Consulate or Spanish authorities.
Our role is to ensure that documents are prepared accurately, consistently, and in a form commonly accepted by Spanish authorities. As a result, clients avoid rejection, delay, or the need to redo the process.
If you would like us to review your documents or coordinate solicitor certification and Apostille, you may contact Ginkgo Advisory for further information.
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