mailboxMail Services

[Get Adobe Acrobat Reader free here]

U.S. Postal Standard Address Format Required for Automated Presort First-Class Discount Rates

Effective July 1, 1996, the U.S. Post Office enacted its Classification Reform to expand the mail volume processed by its automated mail processing equipment. This Classification Reform affects the address quality standards of all letter mail which is submitted for presorted first-class discounts. In order to receive the rate of $0.305 to as low as $0.27 a letter your mail must conform to the following standards:

Physical Characteristics


2.5 oz., Zip+4
3oz., Barcoded 

Card Size:



Shape: It is important that a letter-size mail piece be longer than it is tall (rectangular, not square) so that the mail doesn't tumble during processing.

Aspect Ratio: The aspect ratio for letter-size mail provides a measure tool to determine proper length to height ratio. Dividing the length by the height must yield a result between 1.3 and 2.5 (length divided by height= 1.3 to 2.5).

Polywrapping: Polywrap, poly bag and shrinkwrap material are prohibited for use on mailings submitted at automation-based rates.

Tabbing: Letter-size pieces not sealed on all four edges (folded self mailers, booklets, double postcards) must be tabbed to avoid jamming during high speeed processing in postal equipment. For type of tabbing and placement requirements, please see Exhibit 3-3 [PDF].

Ink Acceptance Criteria: The paper stock used to make a mail piece must have ink absorption properties to ensure that the metered postage and waterbased barcode ink will dry without smearing.

Optical Character Read Area (OCR): All address information must be placed within a specific area for machine readability and a barcode clear zone must be provided for barcode application. Please see Exhibit 4-7 [PDF] for mail piece Clear Zones and OCR Read Area.

Placement of Information

Return Address and Endorsements: The return address should be at top third and left half of mail piece. Endorsements such as "Address Correction requested" must be clearly spaced at least 1/4" below the return address. For additional endorsement placement location areas see "Move Update Requirement."


Readability Insert Shift: Window envelopes and inserts must be designed so that the entire address and a clear space of at least 1/8" appears in the window during the insert's full range of motion within the envelope.

Typography: Address information must be cleanly machine printed with adequate even spacing between characters, words, and other lines of address. Address lines cannot be skewed (slanted) more than 5 degrees. Please see Exhibit 4-15 [PDF] and Exhibit 4-17 [PDF]

Automation Addressing: Addresses on your mail piece need to be machine-printed, with a uniform left margin. The OCR can read a combination of upper and lowercase characters. To conserve character spaces, OCR does not require punctuation.

Logo and Teaser Copy: For example of proper placement of logos and teaser copy see Exhibit 4-19 [PDF] and Exhibit 4-20 [PDF].

Typeface Selection:

Standard Address Format

(Opitional) Nonaddress data 
(Optional) Information/attention 
Delivery address 
Post Office,state,zip 
236 SUNSET AVE RM 101 
LOS ANGELES CA 90012-0001 

Type Size: Required type sizes are between 8 and 18 points.
8 points (Minimum)
10 points (Preferred)
12 points (Preferred)
18 points (Maximum)

Display Type: Stylized and script printing may not be used on mail claimed at automation rates. Do not use type styles defined as light, bold, extended, script-like styles. For OCR readable type forms see Exhibit 4-21 [PDF].

Contrast: Address information must sharply contrast from the background on which it is printed. Black printing on a white background is recommended. The use of fluorescent or phosphorescent paper or inks is not recommended. Resolve any issue about print, design, and color with Mail Services or postal personnel before producing your mail piece.