What are retention periods?

There are two types of mailer endorsements you can add to your envelope - unofficial retention period and ancillary services. Both tell the recipient’s Post Office what to do with the item if it can’t be delivered.

The retention period endorsement printed on your envelope gives the Postal Service guidelines on how long to hold onto undeliverable mail before returning it to you. Typically, undeliverable mail is returned after fifteen days, but you can opt to have the item returned after three, five, seven, or ten days.

You can include up to seven lines in your address. However, adding one endorsement will reduce the number of lines available for your address.