The Requirements of CASS Certification

CASS Certification Requirements
Author: Mary Elizabeth.     Published on: April 7th, 2022

The Requirements of CASS Certification

1000 653 Mary Elizabeth

There’s nothing more important in the mail world than the accuracy of a receiver’s address. Before a single piece of mail or a package is able to be successfully delivered, an accurate address is required. In order to help facilitate smooth business operations and avoid costly shipping delays, companies can implement CASS software that assists in the address verification process. This helps to avoid processing delays while keeping customer information accurate.

What is CASS?

CASS Certification RequirementsCoding Accuracy Support System, or CASS, is a certification mechanism provided by the United States Postal Service® for various mail service providers. This helps to reduce the total amount of errors that can occur when mailing a package or piece of mail. You may have seen an instance of CASS being used when ordering a product or service online. When typing in an address, CASS-certified software solutions utilize various algorithms and databases to correct address field inaccuracies or formatting issues by instantly validating the address. This helps to maintain continuity when shipping to ensure packages are delivered in a timely manner.

For example, typing the following address would show how a typical address may look before and after a CASS-Certified system corrects an address for formatting:

Before the Address Matching:

30700 Russel Ranch


Weslak Village ca 91365

After the Address Matching:

30700 Russel Ranch Rd,

Suite 250

Westlake Village, CA 91362-9507

Since the software can verify addresses from a certified and accurate address database, common mistakes that would otherwise interfere with the shipping process are instantly corrected.

CASS Certification Explained

The CASS Certification process allows for testing and certification by the USPS® to issue a graded measure of a company’s address verification tools. This testing standard is uniform both in approach and results to ensure accurate information is always provided to a business prior to shipping.

The CASS Certification involves two stages. The first stage is voluntary and is used as a self-assessment. The second stage requires a high degree of accuracy in order to receive certification.

Stage 1

This is an optional self-administered test that is used by developers to measure and diagnose an address matching software. Although it’s not graded by the USPS®, this allows development teams to gain insightful information on the current accuracy and capabilities of the software’s current iteration.

Stage 2

This stage tests and evaluates the address matching software in order to receive the initial certification. Once a specific accuracy measurement has been reached, CASS Certification is issued to the software developer. After this point, the certification must be renewed periodically to stay compliant with any future requirements.

Why CASS is Vital for Accurate Address Validation

One of the biggest benefits of CASS Certified Software is that it validates the address before it ever enters your company’s internal customer database. This aids in gathering the correct information so customer packages aren’t delayed due to incorrect information. Any address abnormalities are corrected in real-time according to USPS® standards.

For end-users, this results in their packages arriving on time and at the correct location. For businesses, this helps ensure an overall reduction in shipping delays from incorrect addresses as well as reducing customer service hours needed for address correction.

Additionally, CASS can be used to sort through existing customer addresses within a given database to correct outdated, incorrect, or missing information such as street names, ZIP+4, and carrier route coding.

Maintaining CASS Certification

To maintain CASS Certification, developers must continuously stay up to date on the latest USPS® address verification standards and requirements. After the initial CASS Certification, development companies must continue to renew the CASS Certification periodically in order to maintain compliance with any new USPS® requirements.


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