Mailing Flat-Size Mailpieces with Magnets

September 2023

PS-354 (201)

This Customer Support Ruling (CSR) describes the preparation of flat-size mailpieces that have enclosed thin flexible magnets, such as those designed to be placed on refrigerators or similar surfaces.

The current policy on mailing flats that contain thin flexible magnets, appeared in Postal Bulletin 22221 (12-06-07, page 5), and is specific to thin flexible magnets for flat-size price mailpieces.  All enclosed magnets must have a minimum of 10 poles (the region at each end of a magnet where the external magnetic field is the strongest) per linear inch.

This CSR contains information on mailing flats with magnets, as printed in Postal Bulletin 22221.  

For flat-size pieces with enclosed magnets, the piece must meet the following:

• Magnets may not exceed 1/32 inch in thickness.
• The magnetic surface may face either the address or the non-address side.
• Magnets must be enclosed in the flat-size mailpiece and either must be affixed to the contents, wrapped within the contents to prevent excess shifting, or fill the envelope with no more than 1/2 inch clearance between the left and right edges of the magnet and the mailpiece edge.
• Mailpieces must meet all other relevant standards in Domestic Mail Manual (DMM) 201.

Prior Postal Service approvals for mailpieces with enclosed magnets are still valid if the mailpiece design has not changed since the approval. Customers may seek approval for designs that differ from the above guidelines by contacting their local manager, Business Mail Entry. Managers, receiving such requests must coordinate analysis and testing with the Pricing and Classification Service Center.  

Mailpieces that may be transported by air, such as those mailed at First-Class Mail prices, or USPS Marketing Mail mailpieces that are drop shipped using Priority Mail Express or Priority Mail, Open and Distribute, also must meet the standards for magnetic materials in Publication 52, Hazardous, Restricted, and Perishable Mail, section 349.24. A magnetized material is regulated as a hazardous material when it is presented for air transportation and has a measurable magnetic field strength greater than 0.00525 gauss at 15 feet.

The Postal Service reserves the right to rescind this CSR if we discover any operational impacts due to this support ruling.

NOTE: The Postal Service policy regarding magnets enclosed or attached in letter-sized mailpieces is outlined in Customer Support Ruling PS-351.

(Signed)

Dale E. Kennedy

Director

Product Classification

Headquarters, US Postal Service

Washington, DC  20260-5015