Table of Contents

USPS ZIP+4 (Full ZIP9)

Geocodio can return USPS ZIP+4 codes along with some deliverability indicators for US locations, including PO Boxes.

You can download an example spreadsheet of addresses with ZIP+4 added here.

Data returned for ZIP+4 data appends

ZIP+4 and ZIP 9

ZIP+4 Range Start
ZIP+4 Range End (or blank if no range)
ZIP 9 Range Start
ZIP 9 Range End (or blank if no range)

The range of ZIP Codes that are associated with this result as representated by the minimum and maximum number.

The ZIP9 code consists of the ZIP5 code, a dash, and the +4 code.

In most cases a single ZIP+4/ZIP 9 code is associated with a location, so the second column is left blank. Some larger businesses may however have multiple ZIP+4 codes assigned to a single address.

If a second address line (i.e. apartment/unit number) is applicable for the given building, it is also required to determine the correct ZIP+4 code.

Record Type

Record Type Code
Record Type Description

The type of ZIP+4 result. Possible values are:

  • F: Firm
  • G: General Delivery
  • H: High-rise
  • P: PO Box
  • R: Rural Route/Contract
  • S: Street

Carrier Route ID

Carrier Route ID
Carrier Route Description

A 4-byte code that determines the type of postal route that that servers the address. Possible values are:

  • Bxxx: PO Box
  • Hxxx: Contract
  • Rxxx: Rural Route
  • Cxxx: City Delivery
  • Gxxx: General Delivery

Building or Firm Name

Building or Firm Name

A USPS-provided name associated with the address. This is available for businesses that have registered their name with USPS and for most federal and state government buildings including schools and offices.

The building or firm name field takes the secondary address unit into account if available.

If no name is available, the value is blank.

Government Building

Government Building Code
Government Building Description

Type of government building (if applicable).

If no name is available, the value is blank.

  • A: City Government Building
  • B: Federal Government Building
  • C: State Government Building

  • D: Firm Only
  • E: City Government Building and Firm Only
  • F: Federal Government Building
  • G: State Government Building and Firm Only

Facility Code

Facility Code
Facility Description

Facility code associated with the 5-digit ZIP Code

Possible values are:

  • B: Branch
  • C: Community post office (CPO)
  • N: Non-postal community name, former USPS facility, or place name
  • P: Post Office
  • S: Station
  • U: Urbanization

City Delivery Indicator

City Delivery?

Indicates whether our not the local post office has a city delivery carrier route.

Valid delivery area

Valid delivery area?

In some cases an address exists but it is not a valid delivery point for postal purposes. This could for example be because it is an undeveloped lot.

Exact match

Exact Match?

An exact match means that there was no ambiguity with the lookup and that the given ZIP+4 code is the correct and only match for the given address.

Most often, not-exact matches are due to lookups for an apartment or office building that is missing a unit/apartment number.

In these cases it is not possible to determine an accurate ZIP+4 code without supplying secondary address line information.

Add ZIP+4 data to addresses or coordinates via API

If you'd prefer to use an API instead, see our technical documentation here.