Postal Requirements

The U.S. Postal Service establishes and publishes in the Domestic Mail Manual (DMM) an extensive list of requirements with which business mailings must comply. These requirements determine (among other things) acceptable envelope sizes, position and sequence of address lines, graphic restrictions, and mandatory "clear zones".

While it is impossible to list all the requirements, here are a few which should prove helpful. Consult with your local Postmaster where envelopes will be mailed from, on any additional questions you may have.

Clear Zones

* When the envelope is addressed with a name, address, and zip code, the Post Office will read the zip code with an OCR (Optical Character Reader) and print a barcode on the envelope in the lower right hand corner. This is why you must keep a "clear zone" on the lower right hand corner of the envelope (now ⁵/8" up from the bottom and 4 ³/4" out from right edge).

Bar Coding

* The Post Office has recently found a way to more completely automate letter sorting in first, second and third class mail. This involves the software to transform a Zip+4 zip code into a larger barcode, called a Delivery Point Barcode (DPBC), which designates a specific city block, an apartment house, or even a particular floor in a large office building.

* This coding enables the automatic sorting of mail exactly to a carrier's delivery route, eliminating time consuming hand sorting by as much as 50%. This new, larger barcode is the basis for the new postal requirements for a larger "clear zone" (from 4 ¹/2" to 4 ³/4" out from right edge in the lower right hand corner of the envelope when the mailer does not put the barcode on himself). Mailers must develop the capability to put their own expanded barcode on those pieces of mail that they barcode themselves. They are not allowed the pre-sort discount associated with barcoding unless they comply with the new expanded barcode guidelines.

Additional Postal Requirements