Change-of-name and surname certificates
Changing a given name or surname is done under the Person Name Act B.E. 2505, and the registrar issues a certificate as evidence. That certificate links the old and new names when documents are filed abroad.
When a person changes a given name or surname, the registrar issues a change-of-given-name certificate (form Chor 3) or a change-of-surname certificate (form Chor 5). It is the only document proving that the old and new names belong to the same person, which makes it critical in cross-border files.
The common problem is older documents — birth certificate, degree, employment letter, marriage record — still bearing the former name while the passport and current papers show the new one. Without the change-of-name certificate and its translation, the receiver may treat the file as inconsistent and refuse it.
Marriage or divorce may also change a surname under the spouses' agreement on surname use. There the evidence is the marriage or divorce registration and the related agreement record, together with any certificate the registrar issues when the entry changes.
Assemble the legalisation set in chronological order: former-name documents, the change-of-name certificate, then current-name documents, all translated, so the receiving officer can follow the whole naming history at once.
Documents to prepare
- The original or a certified copy of the Chor 3 or Chor 5 certificate
- ID card and house registration showing the current name
- The former-name documents that will be filed alongside
- Marriage or divorce registration where the surname changed on marriage or divorce
- The passport that will be filed
Step order
- Collect every change-of-name certificate ever issued, not only the most recent
- Translate the certificates and the former-name documents with consistent spellings throughout
- Add attorney copy certification where the receiver requires it
- File the translations for legalisation at the Department of Consular Affairs
- Endorse at the destination country's embassy where that country requires it
Pre-filing checklist
- Every certificate from every change is present, in chronological order
- The new-name spelling in the translation matches the current passport
- The former-name spelling matches the older documents filed with it
- The national ID number is identical across all documents, proving one person
- Every copy carries a complete certification signature
Practical tips
- Add a one-page index of the naming sequence so the receiving officer can follow the file quickly
- If the name changed several times, translate every certificate — do not skip intermediate ones
- Confirm whether the receiver wants originals or certified copies
- Keep a digital set of the legalised translations for reuse in later matters
Common pitfalls
- Filing former-name documents without the change-of-name certificate
- Translating the certificate with a spelling that differs from the passport
- Translating only the latest change, leaving a gap in the naming history
- Relying on the marriage record alone when the receiver asks for the registrar's certificate
Frequently asked questions
Must all older documents be amended after a name change?
No. They record the facts as at their issue date. Attach the change-of-name certificate with its translation to prove the same person is involved.
If the name changed several times, must every certificate be translated?
Yes, in chronological order. Receivers need an unbroken naming history; a missing intermediate certificate breaks the chain of evidence.
Which document proves a surname change on marriage?
The marriage registration and the agreement on surname use, plus any registrar certificate issued when the entry changed, if the receiver asks for it.
What if the certificate is lost?
Ask the issuing registration office for a certified extract from the register, or for a replacement as the registrar's regulations allow; the requirements are the registrar's to set.
Should the translation follow the ID card or the passport spelling?
Follow the passport that will be filed — receivers match against it first — and explain the former name through the change-of-name certificate.
Can you assemble the file for us?
Send the list and scans via LINE @nycli, +66-83-249-4999 or nycli@ilc.ltd. We will order the file, identify what needs translating and set out the certification steps.
For a document review before you file, contact us on LINE @nycli, call +66-83-249-4999 or email nycli@ilc.ltd. Our team will confirm the steps, any missing documents and a realistic timeline for your case.