How can my mother extend her 30-day visa exempt stay in Thailand by another 30 days, and where should we go for the extension?

If your mother recently arrived into Thailand...she would have been stamped in for 45 days as Visa Exempt...vs the 30 days you mention in your post.

Check her passport to look at the entry stamp she has received as an American entering Thailand Visa EXEMPT. It should be for 45 days.

And yes she can get the 30 days extension of stay at Thai immigration office in Bangkok that

@Ellie ******

has posted. Fee is 1,900 Thai baht AND the 30 days extension of stay are ADDED to her current ending date.

She is going to go to IT Square Laksi Plaza temporary office, just next to Lak Si station of SRT Dark Red Line as she entered on visa exempt.

She will go here.



And she can book online here



She should have been stamped in for 45 days not 30 days currently, after Oct 1, 2022.

The 30 days tourism extension will be added to the current stamp, so you wouldn't lose any day even when you go to apply for one in advance.

Attached is a list of the necessary documents for tourism extension. Most likely she wouldn't be asked for a TM30 receipt unless she has a history of staying in Thailand with covid extension(s).