Mailing Letter-Size Mailpieces with Magnets at Automation Prices

UPDATED September 2023

PS-351 (201)

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

The current policy on mailing letters that contain thin flexible magnets, appeared in Postal Bulletin 22221 (12-06-07, page 5), and is specific to thin flexible magnets for letter-size automation price mailpieces.  All enclosed or affixed 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 letters with magnets, as printed in Postal Bulletin 22221, and additional information on affixing magnets to letter-size card-type mailpieces.

For letter-size automation price enveloped pieces with enclosed magnets, the piece must meet the following:

· Magnets may not exceed 1/32 inch in thickness.

· Magnets must only be enclosed in a sealed enveloped mailpiece (Not allowed in unenveloped mailpieces (e.g., self-mailers. booklets)

· The magnetic surface may not exceed 26 square inches (length x height).

· The magnetic surface may face either the address or the non-address side.

· Enclosed magnets must be affixed to the contents or wrapped within the contents to prevent excess shifting, or fill the mailpiece with no more than 1/2 inch clearance between the left and right edges of the magnet and the mailpiece edges.

· The mailpiece must be uniformly thick for processing.

· Automation price letters must meet all other relevant standards in Domestic Mail Manual (DMM) 201.

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For letter-size automation price card-type pieces with affixed magnets, the piece must meet the following:

· Magnets may not exceed 1/32 inch in thickness.

· The magnetic surface may not exceed 26 square inches (length x height).

· Affixed magnets must be positioned on the address side of the mailpiece.

· Magnets permanently affixed to, or prepared as, an integral part of unfolded cardstock pieces must be located on the leading edge of the mailpiece.

· Affixed magnets must be secure with a minimum of three glue lines, one along the right edge, one along the left edge and one in the center of the magnet and extend to each applicable edge.

· Magnets that are affixed with less than 3 continuous glue lines must be secured under a clear poly material, with a selvage of at least 0.25 inch along all four edges of the magnet.  The edges of the poly covering must be affixed to the mailpiece with an adhesive that fully extends to the outer edges of the poly covering.

· The mailpiece must be uniformly thick for processing.

· Automation price letters must meet all other relevant standards in Domestic Mail Manual (DMM) 201.

Prior Postal Service approvals for mailpieces with enclosed or affixed magnets are still valid if the mailpiece design has not changed since the approval. Customers may seek approval for automation prices for mailpieces with 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 in flat-sized mailpieces is outlined in Customer Support Ruling PS-354.

(Signed)

Lizbeth Dobbins

Manager

Product Classification

Headquarters, US Postal Service

Washington, DC 20260-5015