OP, may I recommend that after your death your son gradually runs the account down by withdrawals, but does not empty the account. If emptied the bank may want to see you about closing the account , which would be difficult! Leave a couple of hundred baht in. The subsequent bank charges would run down the (say) 200 baht until there's nothing left, and they will close the account as defunct. Or perhaps I'm wrong, but that's what I've told my wife.