Address validation API for improved address quality.

address validation software

Eliminate database dead-ends by confirming addresses as they enter your system. CASS Certified™ ZIPFOURce™ API is address validation software that lets you add to your front-end process what was once considered a back-office concern: address data validation, standardization, and matching, seamlessly integrated with many Customer Relationship Management and Web-based database applications.

Access USPS™ address information with ease

Once integrated into your current address-maintenance system, ZIPFOURce becomes a gateway to USPS® address information that can make a significant difference to your operations. Understand why certain addresses have been flagged undeliverable, reconnect with lost contacts, and enjoy increased delivery speed.

Cost-effective API

The ZIPFOURce API integrates quickly and easily into most central data applications, and you pay one price for unlimited users.

Delivery Point Validation

Uses USPS DPV® technology to reveal whether an address listed in the ZIP + 4 database is actually recognized by the USPS as a deliverable destination.


Updates rural-style addresses to city-style formats, or renames/renumbers city-style addresses that may have been changed by local governments.

Postal discounts

ZIPFOURce retrieves additional delivery point information, so you can take further advantage of postal discounts.

Target marketing efforts

Access detailed information to gain a robust understanding of every individual in your database.

Multi-platform support

ZIPFOURce is available on Windows and Linux.

Improve connection with current and future clients

ZIPFOURce corrects, standardizes, and matches addresses at the point of entry and does the same for existing data as well, helping you achieve and maintain a clean customer and prospect database.

Residential Delivery Indicator

Interface with USPS RDI™ technology that identifies residential delivery points, allowing informed decision-making when choosing a parcel shipper.


Improve business address data by adding known secondary (suite) details, allowing USPS delivery sequencing where it would not otherwise be possible.


Provides valuable latitude and longitude information.

Available Reports

Reports include PS Form 3553 (CASS Summary), National Deliverability Index, and LACSLink Processing Summary Report.

Download the data sheet and learn more about ZIPFOURce™ API