All mail not bearing a simplified address under 3.0, Use of Alternative Addressing, must bear a delivery address that contains at least the following elements in this order from the top line:
- Intended recipient's name or other identification.
- Private mailbox designator ("PMB" or alternative "#") and number if the mailpiece is addressed to a commercial mail receiving agency (CMRA) address.
- Street and number. (Include the apartment number, or use the Post Office box number, or general delivery, or rural route or highway contract route designation and box number, as applicable.)
- City and state (or state abbreviation). The city is any acceptable mailing name for the 5-digit ZIP Code serving the intended recipient as shown in the USPS City State Product.
- ZIP Code (5-digit or ZIP + 4) where required:
- ZIP Codes are required on Express Mail, Presorted and automation price First-Class Mail, Periodicals mail, Standard Mail, Package Services mail (except single-piece price Parcel Post), all mail sent to military addresses within the United States and to APO and FPO addresses, all official mail (penalty mail), all business reply mail, and all merchandise return service mail.
- Unless required above, ZIP Codes may be omitted from single-piece price First-Class Mail (including Priority Mail), single-piece price Parcel Post, and pieces bearing a simplified address.
Complete Address Definition
A complete address has all the address elements necessary to allow an exact match with the current USPS ZIP+4 Product to obtain the finest level of ZIP+4 code for the delivery address. A complete address may be required on mail at some automation prices.
Complete Address Elements
A complete delivery address includes:
- Addressee name or other identifier and/or firm name where applicable.
- Private mail box designator and number (PMB 300 or #300).
- Urbanization name (Puerto Rico only, ZIP Code prefixes 006 to 009, if area is so designated).
- Street number and name (including predirectional, suffix, and postdirectional as shown in USPS ZIP+4 Product for the delivery address or rural route and box number (RR 5 BOX 10), highway contract route and box number (HC 4 BOX 45), or Post Office box number (PO BOX 458), as shown in USPS ZIP+4 Product for the delivery address). ("PO Box" is used incorrectly if preceding a private box number, e.g., a college mailroom.)
- Secondary address unit designator and number (such as an apartment or suite number (APT 202, STE 100)).
- City and state (or authorized two-letter state abbreviation). Use only city names and city and state name abbreviations as shown in USPS City State Product. Contact the National Customer Support Center (see 509.1.0) for more information about the City State Product.
- Correct 5-digit ZIP Code or ZIP+4 code. If a firm name is assigned a unique ZIP+4 code in the USPS ZIP+4 Product, the unique ZIP+4 code must be used in the delivery address.
Purpose for Return Address
The return address tells the USPS where the sender of a mailpiece wants it returned if the piece cannot be delivered.
Return Address Elements
The return address contains elements corresponding to those for the delivery address. A return address is required in specific circumstances (see 1.5.3). If the sender's name is not included in the return address, another clear designation (apartment, suite, or room number) is required to ensure proper handling of ancillary services and/or return of the piece. ZIP Codes (5-digit or ZIP+4) are required in the return address of all mail on which postage is paid with precanceled stamps or company permit imprint, and in the sender's return address on Periodicals mail when "Address Service Requested" is specified. Official mail (penalty mail) also requires a ZIP Code in the return address.
Required Use of Return Addresses
The sender's domestic return address must appear legibly on:
- Mail of any class bearing a printed ancillary service request or an ancillary service request embedded within an Intelligent Mail barcode.
- Official mail.
- Mail paid with precanceled stamps (except Standard Mail pieces weighing 13 ounces or less and bearing a mailer's postmark in accordance with 604.3.4).
- Matter bearing a company permit imprint.
- Priority Mail.
- Periodicals in envelopes or wrappers.
- Package Services (except unendorsed Bound Printed Matter).
- Parcel Select
- Registered Mail.
- Insured mail.
- Collect on delivery (COD) mail.
- Certified Mail if a return receipt is requested.
- Express Mail if a return receipt is requested. The return address on the Express Mail label meets this standard.
- Detached addressed labels (DALs).
An endorsement directing return to point of mailing (postmark) is not honored.
The USPS uses the return address to provide ancillary services requested by the mailer (e.g., "Return Service Requested"). The return address on any mailpiece endorsed for an ancillary service must identify where the piece is to be returned and where the mailer is prepared to pay applicable postage and fees for pieces returned or for ancillary service provided at the mailer's request. A domestic return address must be placed in the upper left corner of the address side of the piece or the upper left corner of the addressing area.
Attachment of Different Class
If the names and addresses of the sender and intended recipient do not appear on both the host and attachment, the sender's name and address must be placed on one piece and the recipient's name and address on the other. Combination containers that have inseparable parts or compartments are mailable with the names and addresses on only one.
Purpose of ZIP Code
The ZIP (Zone Improvement Plan) Code system is a numbered coding system that facilitates efficient mail processing. The USPS assigns ZIP Codes. All Post Offices are assigned at least one unique 5-digit ZIP Code. Larger Post Offices may be assigned two or more 5-digit ZIP Codes (multi-5-digit ZIP Code offices). Separate 5-digit ZIP Codes are assigned to each delivery unit at these offices.
ZIP+4 - A Complete ZIP Code
The most complete ZIP Code is a nine-digit number consisting of five digits, a hyphen, and four digits, which the USPS describes by its trademark ZIP+4. The correct format for a numeric ZIP+4 code is five digits, a hyphen, and four digits. The first five digits represent the 5-digit ZIP Code; the sixth and seventh digits (the first two after the hyphen) identify an area known as a sector; the eighth and ninth digits identify a smaller area known as a segment. Together, the final four digits identify geographic units such as a side of a street between intersections, both sides of a street between intersections, a building, a floor or group of floors in a building, a firm within a building, a span of boxes on a rural route, or a group of Post Office boxes to which a single USPS employee makes delivery.
Numeric Delivery Point Barcode
A numeric equivalent of a delivery point barcode (DPBC) consists of five digits followed by a hyphen and seven digits as specified in 708.4.2.4. The numeric equivalent is formed by adding three digits directly after the ZIP+4 code.
Additional Addressing Standards by Class
Basic addressing standards for First-Class Mail, Express Mail, Standard Mail, and Package Services are in the Prices and Eligibility section for each class of mail. Additional standards for Periodicals are in 707.3.2, Addressing. Standards apply to overseas military mail, Department of State mail, mail in window envelopes, international mail, and mail claimed at any automation price.