CASS vs NCOA Certification: What’s the difference?

4 minute read

The Postal Service spends most of its day sorting and delivering mail. But when they get a free moment, they like to create acronyms – lots of them, and they are confusing. The average business owner may not fully understand what the acronyms mean or could be unclear about USPS programs like CASS and NCOA. We’ll explain in more detail below, but in brief, think about CASS as being all about addresses and NCOA as a system that relates to individuals, families, or businesses.

CASS (Coding Accuracy Support System) and NCOA (National Change of Address) both support the US Post Office’s goal of accurate and current mailing addresses to improve deliverability. But the two programs are distinctly different. Marketers and operations managers must understand what they are getting when they license software for mailing list maintenance.

Uses of CASS and NCOA

Why Mailing List Correction and Updating Is Significant to the Post Office
Every time a worker touches a mail piece, it costs the USPS money. If the address is wrong or the addressee has moved, the letter cannot be delivered. What happens next? The postal service returns First Class mail to the sender. Marketing mail is generally not returned, but earmarked for recycling instead. Undeliverable as addressed (UAA) documents require more human intervention than mail that bears an accurate and up-to-date address. Getting the addresses right when your organization creates the mailpieces reduces manual touchpoints for the postal service and keeps postage costs reasonable.

Why Mailing List Correction and Updating Is Significant to Business and Non-Profits
Besides the requirements for address accuracy that the USPS requires for mailers to earn postal discounts, three motivations for organizations to validate and update address files supersede all others:

1) Reduce wasted printing, postage, and processing costs.

2) Decrease lost opportunities to sell something or solicit a donation.

3) Lower incidents of costly extra handling and poor decisions based on errant addresses.


CASS (Coding Accuracy Support System)
Often inaccurately portrayed as a process, CASS is actually a certification from the US Postal Service. It verifies the address coding software used by mailers or services meets the USPS’ standards for accuracy. The CASS software certification program provides developers, service bureaus, and commercial mailers a measure to test the quality of address-matching software. CASS certified software is used to verify that required elements of postal addresses are present, spelled correctly, and formatted according to postal specifications.

As an example of the importance of CASS, consider that Atlanta has 71 roadways (streets, parkways, roads, avenues, etc.) that include the word “Peachtree” or some derivative as part of their name.1 The roadways are scattered over nearly 100 Atlanta ZIP codes.2 But if your database lists an address as “123 Peachtree” with no pre-directional (west, east, north, south) and no designator (ave., st., rd., blvd.) your mail will probably not be delivered at the best postage rate. It could be sent to the wrong address or returned to you as undeliverable.

If you used an incorrect address to ship merchandise to a customer, it will eventually come back to you. Undeliverable packages sent via carriers like FedEx or UPS generate return shipping fees. Also associated with undelivered merchandise is customer dissatisfaction, spoilage, and lots of extra labor and expense by your organization to research, re-pack, and re-ship.

When relying on postal addresses for non-mailing/shipping applications, addresses not verified with CASS certified software can cause problems too. Errors in dispatch, customer distribution analysis, tax collection, and more are common.


NCOA (National Change of Address)
NCOA uses address change notifications submitted to the USPS by individuals, families, and businesses to replace old addresses with new ones. If you have completed a move update card or an online move update request for a permanent or temporary move, your information will update the US Post Office’s NCOA database at the National Address Information Center in Memphis, TN. The Memphis facility is the central repository for all moves submitted to the US Postal Service.

NCOA allows organizations to recognize when someone in their database or from a rented marketing list has moved. In some cases, failing to check NCOA can cause confidential information, such as medical or financial data, to be delivered into the hands of the wrong people. In other cases, delayed delivery of forwarded items like bills and invoices sent to movers will trigger late charges and disrupt cash flow.

The two common methods for “NCOAing” lists before mailing are:

1) Sending the list to a service bureau for updating.

2) Using the move update option built into postal presort/CASS/mail management software.

Post-mailing updates are also possible, using the USPS’ Address Correction Service (ACS). However, correcting addresses after being notified of failed delivery or forwarding is not nearly as efficient. Unless the mailer sends to the same addresses repeatedly, post-mailing address updates are not beneficial.

Keeping addresses healthy is a challenge for organizations. 15% of U.S. residents move every year.3 Clerical mistakes also cause inaccuracies when data is manually entered. The USPS maintains NCOA data for moves going back 48 months. To combat Undeliverable as Addressed (UAA) mail, the post office requires any mailing claiming postage discounts to have been processed against the NCOA database within 90 days of the mailing.

NCOA vs CASS Software

Firstlogic® is a provider of CASS-Certified and NCOA address updating and standardization software solutions. They are the leading SAP® Partner specializing in delivering the Firstlogic Data Quality IQ Suite and the SAP Data Services Platform to data-driven companies. Firstlogic and SAP Data Quality software combine file preparation, data profiling, address quality, geocoding, data enhancement, matching, and consolidation. For more than 35 years, customers have leveraged the power of Firstlogic’s data quality platform.