Hi @magicmooly you can check the required document list from the NVC/DOS web site specific to the US Embassy in Thailand.
Assuming the interview will take place at the US Embassy Bangkok - here is the link to see the Pre-Interview Checklist
Please use the list below to determine the items that EACH applicant must bring to the immigrant visa interview:
A copy of your NVC interview letter (does not apply to Diversity Visa, fiancé(e), adoptive, or asylee/refugee applicants).
Unexpired passport valid for eight (8) months beyond your intended date of entry to the United States and a photocopy of the biographic page (where your name and photo are located). Your immigrant visa will be issued in the name which appears on your passport, not on your immigrant petition. Discrepancies should be corrected prior to your interview.
Two (2) color passport-size photographs of each person applying for a visa (5 cm x 5 cm). Please see photo requirements.
Confirmation page from the Form DS-260 Application for an Immigrant Visa you submitted online at ceac.state.gov/iv.
Confirmation page from your online registration of a delivery address for returning your passport and documents after the interview (see Step 1).
Your original birth certificate, English translation, and a photocopy.
If an official birth certificate is not obtainable, applicants should submit a Certificate of Birthplace, their Household Registration, and their Thai National ID card as secondary evidence. Individuals born outside of Thailand should refer to their country of birthplace in the Reciprocity Schedule to determine acceptable secondary identity evidence.
If your name does not match your birth certificate, submit a Name Change Certificate(s), English translation, and photocopy.
Medical examination results in a sealed envelope (if the physician gives you these results).
Original or certified copies of birth certificates for all children of the principal applicant (even if he or she is not accompanying).
Applicants who fall into any category listed in italics below should bring these additional documents:
For family-based visa applications:
The appropriate Form I-864 Affidavit of Support for each financial sponsor along with a photocopy of the sponsor’s IRS transcript or most recent U.S. federal income tax return, and any relevant W-2s.
Proof of your U.S. petitioner’s status and domicile in the United States (photocopy of a U.S. passport, naturalization certificate, or lawful permanent resident card).
Evidence of the relationship between the petitioner and visa applicant (such as photographs, letters, or emails).
If you are married: Your original marriage certificate, English translation, and a photocopy.
If you were previously married: Your original divorce or spouse’s death certificate, English translation, and a photocopy.
If you are applying for a visa in the F11 or F24 categories (unmarried child 21 years or older): An original marital status certificate, also known as the Single Status Certificate.
If you are older than 16 years of age: The original police certificate from your country of current residence and countries of previous residence. If these three items are all true, you must bring a more recent police certificate to the interview:
You are older than 16 years;
You obtained a police certificate and submitted it to NVC more than one year ago; and
You still live in the country that issued the police certificate.
For employment-based visa applications: Letter from your U.S. employer dated less than one month ago.
If you have ever been convicted of a crime: Court and criminal records, English translation, and a photocopy.
If you have served in any country’s military: Military records, English translation, and a photocopy.
If you are adopted: Adoption papers or custody documents, English translation, and a photocopy.
If you are the petitioner’s stepchild: The original marriage certificate of the petitioner and your biological parent, English translation, and a photocopy along with divorce records for any previous marriages of either parent.
For all minor children traveling with a parent applicant or following later: Official grant of permanent custody for minor children is required for all children under 18 years old.