The publisher of each publication sent Periodicals Class Mail, including foreign publications accepted at Periodicals rates, must file Form 3526 by Oct. 1 of each year at the original entry post office. Since Oct.1 falls on a Saturday this year, the post office expects to receive it by close of business on Sept. 30.

The information provided on Form 3526 allows the U.S. Postal Service to determine whether the publication meets the standards of Periodicals mailing privileges.

The required information also must appear in an issue of the publication whose primary mailed distribution is produced:

• Not later than Oct. 10 for publications issued more frequently than weekly.
• Not later than Oct. 31 for publications issued weekly or less frequently, but more frequently than monthly.
• For all other publications, in the first issue whose primary mailed distribution is produced after Oct. 1.

Click here to download Form 3526.