I received a TSEV on Dec 22, needing to request a 30 day extension after 60 days at an immigration office. The stamp in my passport says enter before 20 Mar 2016. What do I need to do in order to extend my stay in Thailand for approximately another month and a half from Mar 20?

Thanks!

Go to a neighbouring country and apply for a Tourist Visa.

A bit unclear.

TSEV= tourist visa, single entry?

You are in Thailand right now using this visa?

If yes: the visa has been used and is void, so "ENTER BEFORE" on the visa is irrelevant.

The real important stamp is the one you got upon entry at the immigration desk.

When did you enter and what does it show for "ADMITTED UNTIL"?

Before the admitted until is over you go to the immigration office to apply for a 30 day extension of stay,

(details ommited)

(chance is that I totally misunderstand the OP)

Edited January 21, 201610 yr by KhunBENQ

Ignore the 'enter before' date (Mar 20th) as you have already entered and the visa is used. The important date is the end of your 60 day permit to stay. You will have a stamp in your passport with an 'admitted until' date. If you entered on December 22nd the date should be February 19th.

You can apply for the extension of stay 7 days before Feb 22nd. Some offices will let you apply up to two weeks early. It doesn't matter how early you apply as the extension will start from February 20th.

Edited January 21, 201610 yr by elviajero

Ignore the 'enter before' date (Mar 20th) as you have already entered and the visa is used. The important date is the end of your 60 day permit to stay. You will have a stamp in your passport with an 'admitted until' date. If you entered on December 22nd the date should be February 19th.

You can apply for the extension of stay 7 days before Feb 22nd. Some offices will let you apply up to two weeks early. It doesn't matter how early you apply as the extension will start from February 20th.