Mail permits are used by businesses and organizations to send bulk mail. They are often used in conjunction with "permit imprints," a method of stamping that actually pays for the postage of sending the items. The permit itself is simply U.S. Postal Service, or USPS, permission to mail mail a certain way. When someone applies for a mail permit, they are given a number associated with their account. This number is imprinted on mail sent using the permit. This number is the method for tracing mail permit numbers, and you must have it available when you go to the post office.

Applying for a Mail Permit

To apply for a mail permit, complete USPS Form 3615, Mailing Permit Application and Customer Profile. There is no fee to apply for a mail permit, although you must pay a one-time fee to set up a permit to mail with permit imprint. This one page form also includes instructions; applicants need to provide their information, as well as the business's, and specify the type of mail permit desired. The post office will then issue a mail permit number for the account.

Mail Permit Labels

Mail permit labels, which specify that a piece of mail is being mailed using a mail permit holder's account, indicate the mail permit number. To trace a mail permit number, a piece of mail containing a mail permit label is helpful, as it shows the post office the specific permit number you desire to trace. You can also jot down the mail permit number from the label, although this may be tricky, as there may be many numbers written on the label, making it difficult to pinpoint which you need.

Tracing Mail Permits

Take a piece of mail bearing a mail permit imprint to the post office and ask the postal worker to trace the mail permit number. You will need to verify that you are either the bearer of the mail permit--the sender--or the recipient of the piece of mail bearing the mail permit. Bring photo identification with you. The post office will be able to trace the mail permit number for you.

Business Return Mail

Business return mail preprinted envelopes and labels also bear information about mail permit numbers. If you have one of these labels, you can follow the same process for tracing the mail permit number to determine who is responsible for the permit. The mail features an Intelligent Mail Barcode, or IMB, with 31 digits. These numbers included coded identification such as the serial number and the mail's routing code.