Banky team Reviewed editorial answerIn a savings account's key-facts statement, the bank states the basis on which the return is calculated; the two most common are:
Daily balance: the return is calculated on each day's balance, so a two-day withdrawal affects those two days only.
Lowest balance in the month: the lowest figure your balance reached on any day of the month is what the return is calculated on for the whole month. So one withdrawal, even if you put the money back a day later, lowers the whole month's base. Fee debits have the same effect.
So if your account uses the lowest balance, plan your withdrawals knowing that the month's lowest figure is what counts.
If your account uses the daily balance and was calculated wrongly, you have the right to complain to the bank: it gives you a reference number at once or within two business days and answers within 15 business days; you can object, and if it is not resolved you can escalate to the Central Bank. Check the balance basis in your account's key-facts statement.