Home > About USPS & News > Forms & Publications > Postal Periodicals and Publications > Publications > Publication 401 - Guide to Manifest Mailing System > 9 Acceptance Procedures > 9-8 Retaining Verification Documents
9-8.1 For each postage verification that does not require a postage adjustment, the acceptance unit must keep the following for 90 days after the mailing:
9-8.2 For each postage verification that requires a postage adjustment, attach the following to the postage statement and give copies to the mailer: