My single entry NIB visa was extended to a year long one when I received my work permit. My work permit and my visa will come to an end on the 1st March. Will I have to leave the country and re-enter on a new visa or can I get a 30-day extension of stay instead and leave at a later date which will be more convenient for me?

Thanks for any help.

Unless you are maried to a Thai antional or have a child with Thai nationality, you have to leave the country the day your job finishes. You can only get an extra 7 day from immigaiton to leave the coutnry, for 1,900 baht.

As Mario said.

However, if you want to you it is possible for you to leave Thailand and then FLY back in and you will get a 30 day stamp on arrival at no cost (except of course for the airfare and travel).

That entry stamp will give you the 30 days you want to settle your affairs here in Thailand.

Or, if you want to go for the whole hog, you can apply in a nearby country for a 60 day tourist visa ... which can then be extended at your local immigration in the last 30 days of that visa .... so you will get a full 90 day stay.

But that tourist visa is NOT free nor is the extension on it.

Is job ending at the same time as your extension and work permit?

If not you can get another 1 year extension and work permit. No need to leave the country.