What is the process for extending a visa waiver in Thailand for UK and Swiss citizens, and what documents are needed?

>Could anyone tell me the earliest date we can apply for the extension, as our current Visa waiver ends on 08.01.22.

Chiang Mai, Bangkok, Buriram, Phuket, Chiang Rai and a couple of others all allow people to apply for extensions when they have 45 days or less left on their current stamp. The other immigration offices are 30 days. However, ask your local immigration office for specific details.

> think the doc's I need are: Passport & copies, Passport sized photo, return air ticket, copy of our TM30

Each immigration office has their own slight differences for requirements. Expect the following to be asked for each person:

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. A TM30, filed in the immigration office.

3. The forms (each immigration office may have different forms, and want to use their special forms)

4. 2x passport pictures

5. 1,900 THB.

Proof of leaving Thailand is NOT required for this extension of stay.

>where do we get [the TM30?]

You will get a copy of the TM30 from your landlord, hotel, or property owner. When you arrived they should have entered you into the system. Proof of submitting a TM30 online will either be the middle or bottom image of the attached picture, depending on the application used.