There is an annual fee for using the ATM cards at most Thai banks – 200 baht. If you have 4 accounts that’s 800 baht every year. If you keep your accounts for 5 years – that’s 4,000 baht. It adds up – especially for Thais with low income!
Check fees are 300 baht for 20 checks at some banks. That’s 15 baht per check!
Currently the interest on bank accounts is less than 1%.
One positive note – the fee for transferring money between banks at the ATM machine is reasonable – under 30 baht in all cases I know of.