Address Validation FAQs

What is address validation?

Address validation verifies addresses for accuracy against current USPS data and makes corrections to delivery lines and last lines when possible. Address validation occurs automatically as part of Address Validation APIs and Create Shipment APIs that use USPS. You can choose whether to use complete address validation (the default) or minimal address validation. For a comparison, see What is minimal address validation? below.

What is minimal address validation?

If an API request uses address validation, the request verifies addresses against current USPS data and makes corrections to delivery lines and last lines when possible. You can optionally limit the extent of corrections by enabling minimal address validation when making the API request. The following table describes both complete address validation, which is the default, and minimal address validation. To enable minimal address validation, see the API request’s documentation page.

Complete Address Validation
Minimal Address Validation
Evaluates the entire address against the current USPS address information. Evaluates the entire address against the current USPS address information.
If current USPS address information indicates no delivery to the address, the API returns an error. If current USPS address information indicates no delivery to the address, the API returns an error.
If the address cannot be validated against current USPS address information, the API returns an error.

If the entire address cannot be validated against current USPS address information, the API checks whether just the last line (city/state/postal code) can be validated:

  • If the last line cannot be validated, the API returns an error.

  • If the last line can be validated, the API checks whether the delivery line (street address) has the correct format (e.g., a street number and street name). If it does, the API returns the address with any corrections only to the last line.

    The API does not verify or change the delivery line. The API returns the delivery line exactly as it is specified in the request.

    The API does not provide a ZIP+4 or 2-digit delivery point.

    If you use minimal address validation, ensure the delivery line you enter is actually deliverable.

If the API determines the address is a match or close match, the API returns the address with any corrections. The API also returns the ZIP+4 and the 2-digit delivery point. If the API determines the address is a match or close match, the API returns the address with any corrections only to the last line. The API also returns the ZIP+4 and the 2-digit delivery point.