USPS Form PS 5630 is many times called a SCAN form. It is used to expedite acceptance and provide a receipt of mail acceptance.
The SCAN Form contains a large bar code that links to all the Certified Mail™ items as well as Priority Mail™ and Priority Express™ items accepted by the letter carrier or postal service clerk. The SCAN form works like this: leave your mail and SCAN form in your mail receptacle or present them to a USPS mail clerk. The letter carrier will SCAN the large bar code then return the form as a receipt of acceptance. The electronic SCAN records the date and time of each letter or package mailed that day. This single scan activates the USPS tracking system that records the official “Shipment Accepted” status for each item including the date, time and name of local Post Office accepting the mail. This is many times used as evidence or proof of mailing for regulatory or compliance reporting.
The SCAN Form is optional, but if you need it, it must be created before 7:00 PM EST the same day as the labels.