13-Ounce Rule

Beginning July 30, any mail placed in a collection box that weighs more than 13 ounces and bears only stamps as postage will be returned to the sender.

Currently, mail weighing 16 oz. or more must be taken to a post office for processing. According to USPS, the change was made to reflect the threshold between First-Class Mail and Priority Mail as well as for heightened security reasons.

USPS is distributing a new decal (shown above) for collection boxes announcing the change.

The Postal Service also is eliminating the “Known Customer” designation. That means city carriers and rural carriers as well as contract and delivery service suppliers — highway contract carriers — will no longer be allowed to accept stamped mail weighing more than 13 ounces from a customer or a customer’s mailbox.

Rural carriers and contract and delivery service suppliers will, however, be able to accept mailpieces more than 13 ounces that require a retail transaction and that have a return address matching the point of pickup.