In most provinces you can apply for your extension with 30 days or less remaining (some 45 and some just 7). You ask your hotel/landlord for a copy of the TM30 soon after check in as they can only print a copy up to day days after registering you.

@Tony *******

no, no video anywhere

What does the website say?

@Peter **********

not with a single entry visa

There is no online application in country, you find a school, get the required documents (this takes longer than 15 days usually) then you go to Immigration to apply for your Visa.

@John *********

no appointment necessary in Sa Kaeo province, walk in, register etc. and out in 75 minutes with my 2 year DL.

@Paul **********

no we don't, not for the 2 year initial Thai DL. I got mine in Sa Kaeo province a year ago, no video, just the 3 tests, completed in 75 minutes from arrival to departure. 5 year renewal is different. Visa is not (always) irrelevant as I had to provide a copy. It differs from province to province so there is no one fit for all, this is Thailand (TiT).

@Leigh ***********

it's all above what's needed

@Paul **********

Without a IDP the OP may have take the video test (depending on the province maybe) plus a copy of a valid Visa

@Katrina *******

TM30 is the registration of a foreigner staying and it is normally done online by the hotel/landlord which creates a PDF that can be printed when required