The overdue deduction by the Postal Savings Bank is the small account management fee owed to the Postal Savings Bank. Postal banks refer to state-owned commercial banks. China Postal Savings Bank was formally established on March 20th, 2007. It is a state-owned commercial bank established on the basis of the reform of postal savings management system. Late payment means that you owe a small account management fee. If the average daily deposit balance of personal current savings account is less than that of 300 yuan, the bank will deduct a small fee of one yuan per month, which is generally deducted on the interest-bearing day at the end of each quarter. If you have no money in your account at that time, you owe it to the bank. You can make it up next time you have money. So it refers to the small account management fee owed by the Postal Savings Bank.