Just to clear things up so nobody else mentions it.

I couldn't ask the bank as it was a Sunday night, and 200bht didn't scream immediate threat anyway. I thought the renewal fee was 400bht, so asked on here to see if anyone knew what 200bht could be for.

Even though I paid the renewal fee 7 months ago, due to the months I opened my accounts and the dates I've been in Thailand I was likely over the 12 month period both times on at least one of my accounts. I might not be charged the 200bht on my other accounts until July. Who knows?

the OP raced through a National Park gate without paying.

they traced him and informed his bank.

OP: why don't you phone the ban and ask them?

Great advice, assuming the OP has reasonable Thai skills. Three banks in our town and the English language ability of the staff comes under diddly and squat.

If you want to save some phone minutes, next time you can use the internet banking "send us a message" feature. They usually email back very quickly....within a day.

Indeed it seems to be a card fee charge - did you just get card/open account, or one year ago by chance? If you used passbook to take money out there should be an entry code to explain the 200 baht.

Yes, look for the 2 or 3 letter code associated with the 200B deduction from the account. My account's not at Bangkok Bank specifically, but there's probably a legend somewhere in the bank book, probably at the back (if not, then online maybe). If you haven't made any charges yourself from the account (e.g., like topping up your phone sim), I also agree that the charge is most likely an initial or annual renewal fee for the card associated with the account.