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.
Checks issued as part of the Independent Foreclosure Review Payment Agreement expire 90 days after they are issued as a means to limit fraud. If your check has expired, please contact the paying agent, Rust Consulting, at 1-888-952-9105, Monday through Friday, 9 a.m. - 8 p.m. ET or Saturday, 11 a.m. - 4 p.m. ET.