What extension should I apply for if my 30-day visa in Thailand expires on the 21st and I need to stay until the 28th?

If your 30 day visa exempt stamp expires on the 21st, you can ask for a 30 day extension of stay based on tourism. You will need the following documents:

1. Your passport and:

a. a copy of your data ("picture") page

b. a copy of your most recent visa (if you have one)

c. a copy of your most recent stamp

d. a copy of your departure card

2. [Might not be asked at Bangkok Immigration] A TM30, filed in the immigration office.

3. The forms (each immigration office may have different forms, and want to use their special forms). For Bangkok Immigration, the forms are found in the FILES section of this group

5. 2x passport pictures

6. 1,900 THB.