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About MERLIN  
MERLIN™ program
All business mailings presented for acceptance must be verified to confirm their eligibility for reduced postage rates. Verifications are separated into two categories:

Initial review – Business mail entry clerks inspect a mailing for fees, funds, and eligibility.
In-depth review – MERLIN uses a sampling procedure to produce reports for each verification.

What can MERLIN do?
MERLIN verifies First-Class Mail®, USPS Marketing Mail™, and Periodicals mail against the standards set in the Domestic Mail Manual (DMM®) for:

Postage discounts

It automates the previous manual acceptance process for First-Class Presort Mail, USPS Marketing Mail and Periodicals to qualify for workshare discounts.

What can be analyzed by MERLIN?
MERLIN processes letters, postcards, and flat-size pieces that meet the following criteria:

Maximum length – 12 inches
Maximum height – 15 inches
Maximum thickness – ¾ inches
Maximum weight – 16 ounces

How are samples selected for testing?
The PostalOne! system determines the number of trays or bundles to be verified. Samples for MERLIN verification are then randomly selected by the acceptance clerk.

How does MERLIN analyze mail and provide results?
The U.S. Postal Service processes the selected samples on MERLIN to verify that the mailpieces qualify for the rates claimed. After MERLIN has completed running samples, it analyzes the data and provides the MERLIN operator with reports to be shared with the mailer.

How do I appeal MERLIN results?
If your mailing has not passed MERLIN verification, you can request a second level review with U.S. Postal Service acceptance personnel. If you are unable to resolve it, you may elect to appeal the results.