does Thai immigration charge for even one day overstay and how much do they charge?, thank you.

They MAY give you 1 day. But its 500 baht per day up to a total of 20,000 baht.

Some Immigration offices allow 7 days after the due date but l would recommend you get it done asap

Immigration at the airport will allow you one day if you are only one day over.

Otherwise there is no grace period. 500 BAHT a day up to a max of 20,000.

A post giving illegal advise has been deleted.

Overstays cost Bhat 500. per day. If you have an air ticket out for the following day, ie within 24 hours of the overstay but not longer than, they may not charge you. The maximum overstay fine is Bhat 20,000. Some posters here have overstayed 3 years and will pay the 20,000 Bhat. So 500 per day to a maximum of 20,000 bhat. Late 90 day reporting is Bhat 200. per day. They only accept cash.

Late reporting of 90 days stay is usually a fine of 2,000 Baht.

There is a window of plus and minus 7 days.

Some Immigration offices allow 7 days after the due date but l would recommend you get it done asap

You don't specify overstay for what? 90 day reporting or returning? Generally correct, have had no problems with either Phuket nor Bangkok immigration being a few days late especially if not close to an immigration office and can document that and was told by Bangkok that there was a week's grace period and just reported 1 day late recently without issue..

I think a couple of posters are confusing 'overstay' and '90 day reporting'.

The OP asked about 'overstay'. So, unless the OP was also confused, and used the wrong terms, the 7 day grace period is not relevant.

I think a couple of posters are confusing 'overstay' and '90 day reporting'.

The OP asked about 'overstay'. So, unless the OP was also confused, and used the wrong terms, the 7 day grace period is not relevant.

I was assuming the OP was talking about 90 day reporting. If renewal of 1 year extention of stay it should be done before the due date so to ensure all the documents required are in order

I am on a 1 year multi non-imm 'O' (have had 3 or 4 now). My next leaving date according to the stamp in the passport is next wednesday 15th sep, but it would be far more convenient if i could leave a week later (for a 10 day trip to europe). Apart from 3,500 baht of fines at the airport, is there any other sanction that will be imposed, or could it cause problems getting my next 1 year visa ?

thanks

If not arrested and jailed the fine is likely to be the only issue under current policy. But it would be far safer making a border crossing/return for 15 days if you are eligible for visa exempt entry.

If not arrested and jailed the fine is likely to be the only issue under current policy. But it would be far safer making a border crossing/return for 15 days if you are eligible for visa exempt entry.

If only it wasnt 4 hours (at best) to the nearest border, and then a boat, which i am not that enthusiastic about if its a bit windy i would do it...