Why Does DocuSend CASS My Addresses?

(And What Is CASS Anyway?)

Authored by: Dave Drum.

CASS Certification, US mailing.

CASS certification helps save money on postage.

The acronym CASS stands for Coding Accuracy Support System. The United States Postal Service keeps a database of every address within the U.S. in order to facilitate the automation and accuracy of the mailing process. We match our customers’ addresses against this database to give you the full benefit of this powerful tool.

CASS certification lets us assist the USPS in processing your mail.

Why is this important to you?

Because when we CASS your addresses, the postal service grants us a work-sharing postage reduction, which is one of the reasons we can give you DocuSend’s low all-in-one pricing.

Over 10 Years in Use

CASS certification became available in the late 1980s as an extension of the USPS' work-sharing discount program, which began in 1983.

How It Works

The CASS certification system uses software that matches entries in an address list with entries in the USPS national database via AMS (Address Matching System).


The CASS matching process verifies that addresses are either correct and deliverable or incorrect and undeliverable. The USPS provides feedback regarding the results, which you will see when you review your documents.The DocuSend website shows you how the address should look.*

The Bottom Line

CASS certification enables mail owners to hold the cost of mailing in check. Additionally, and certainly not minimally, it improves the ability of mail carriers to deliver mail accurately and in a timely manner.

Updated on August 6, 2020

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About the author
CASS US mailing

Dave Drum is an expert in the mailing industry and has spent the last four decades in both sales and production. Dave and his wife Kim live in Rochester. Dave is a superb drummer and you can often catch him playing with local bands on the weekend. In their spare time, they love traveling to beaches in the Caribbean.

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