The recent Revision D of the Intelligent Mail barcode specification (07/24/07) contained notable changes from the previous release, such as new height tolerances and changes to the Mailer ID construct. The previous Intelligent Mail barcode specification allowed a barcode height between 0.134 and 0.230 inch. Revision D allows the barcode height to be between 0.125 and 0.165 inch. In addition to shorter barcode height, Revision D allows a minimum clearance of 0.028 inch above and below the barcode; the 0.125 inch minimum clearance on each end of the barcode remains unchanged. To further ease the transition to the Intelligent Mail barcode, the latest Revision E of the Intelligent Mail barcode specification (10/30/07) allows for larger void (dot matrix spacing) tolerances. If you are printing the Intelligent Mail barcode using inkjet technology and are concerned about voids, the allowable spacing between dots has been increased from 0.005 to 0.010 inch. All resources on this website (http://ribbs.usps.gov/onecodesolution) have been updated to reflect these changes.

Mailers and mail preparers using the Intelligent Mail barcode have until January of 2009 to implement the tolerances of the current specification and transition to the more elegant shorter-height barcode.