Once you reserve a PO Box at the Post Office location, link it to your USPS.com account. You can manage it online instead of the Post Office location. Link a PO Box to an USPS.com Account
Quick Answer. Cashier's checks themselves do not expire as personal checks do. However, the funds behind the check are subject to state escheat laws.
AndreyPopov/iStock/Getty Images. The U.S. Department of the Treasury issues checks authorized by federal agencies for payment of benefits or, in the case of the Internal Revenue Service, tax refunds. Treasury checks expire one year after the date of issue. Banks will not accept the expired check for cashing or deposit.