The Thai Marriage Visa or "O" visa is usually issued by the Thai Embassy as a single entry visa. That means that the Marriage Visa issued is only good for 90 days stay in Thailand. The Marriage Visa may be extended in country at Thai Immigration for 1 year at a time with the following rules in place. The rules or requirements for the Thai Marriage Visa extension are as follows:

These are the requirements for the extension of the Thailand Marriage Visa:

Requirements:

1. Application Form (T.M. 7)
2. A copy of your passport or document used in lieu of passport
3. Work Permits (If being employed)
3.1 The applicant’s 2x2 inches photo.
3.2 Letters of Employment stating title and income (If being employed).
3.3 Bank Statement together with a certified letter from the bank.
3.4 Copy of Marriage Certificate.
3.5 Copy of House Registration. (Thai National Spouse)
3.6 Copy of I.D. (Thai National Spouse)
3.7 Copy of Birth Certificate (If there is any children)
3.8 Tax Certificate Por.Ngor.Dor.1, Por.Ngor.Dor.91 (If being employed)
N.B. Please bring original documents along.