USPS CASS Certification vs. NCOA Certification — Which Is Better?

USPS CASS Certification vs NCOA Certification

CASS (Coding Accuracy Support System) and NCOA (National Change of Address) are two methods of address data verification. CASS tells you if an address can receive mail. NCOA provides the current address for your recipient assuming they have filed a USPS change of address within the last 48 months.

That’s the most high-level explanation. To break it down a little more:

CASS is a tool created and used by the United States Postal Service to ensure the accuracy of any software that taps into their database. A CASS-certified service provider that processes addresses will fill in information missing from an address, standardize it, and update it, giving you the most current and most accurate address.

NCOA is an address database maintained by the USPS of all individuals and companies who completed a Change of Address form in the previous four years.

While both CASS and NCOA were created and are used by the USPS, when it comes to address validation, or verification, one of these systems is far more reliable than the other.

SmartyStreets is a USPS CASS certified vendor that you can use validate addresses in many ways with our world-class tools.

Single Address Tool Bulk Address Tool Address Validation API Address Autocomplete API

But let’s back up and tell you a little bit more about CASS certification and NCOA certification and why different address validation service providers might offer one and not both.

In this article, we'll cover,

What Is CASS Certification?

USPS CASS Certified

The CASS (Coding Accuracy Support System) certification process was designed by the USPS in cooperation with the mailing industry to improve the accuracy of Five-Digit ZIP Codes, ZIP + 4 codes, delivery point (DPCs), and carrier route codes that appear on mailpieces.

CASS certification is available to all eligible software developers, commercial mailers, and service bureaus who wish to evaluate the accuracy of their address matching software programs. Software tests for CASS certification are graded by the USPS and the National Customer Support Center (NCSC).

In order to be eligible for CASS certification, your address processing software needs to use delivery point validation (DPV) and a locatable address conversion system (LACS). (Spoiler alert: SmartyStreets uses both of these!)

DPV: Delivery Point Validation

Delivery point validation is a system where address verification software asks the USPS, “do you deliver to this address?” and USPS software returns a simple yes or no response. DPV is the most specific and accurate version of validation.

LACS: Locatable Address Conversion System

LACS is an address database maintained by 911 emergency services to make sure that a location can be found in case emergency services are needed. It keeps track of addresses that have been updated in order to match a national standard, which is used to make finding locations easier in an emergency.

The CASS certification process has two stages:

Stage 1: CASS Test With Answers (optional)

The first stage is kind of like taking an open book final exam. The USPS provides a test file of approximately 150,000 test addresses—as well as the answers. The test file addresses are extracted from the City State and ZIP + 4 files, with samples of all types of addressing used around the country. Some test addresses have been changed for test purposes, and not all records are valid addresses.

Software providers, like us at SmartyStreets, can test their software’s accuracy using this test file and do any debugging or updates necessary based on the results. The results of this test have no impact on certification.

Stage 2: CASS Test Without Answers (required for certification)

The CASS Stage II file contains approximately 150,000 test addresses in the same makeup and mixture as Stage I—but without answers. Customers use their address-matching software to apply the correct data applicable to the test record.

To become CASS-certified, vendors must pass with a minimum score of 98.5 percent for ZIP + 4, carrier route, Five-Digit ZIP, and LACSLink, and 100 percent for delivery point coding, eLOT, DPV or DSF2, RDI, and Perfect Address. There’s no grading on a curve here!

To remain CASS-certified, developers must reapply for certification every two years and meet the minimum accuracy requirements during Stage II testing.

Why Does CASS Certification Matter to YOU?

What this all means is that an address processed by a standardizer or address validator that uses CASS-certified software is more reliable than an address that wasn’t validated by a CASS-certified software.

In addition, if you want to get the mailing discounts the USPS offers for automation-compatible mail, you must be using an address list that was properly matched and coded with CASS-certified address matching methods. Automated mail processing equipment speeds up the process and is less effort for the USPS, but since the mailing address is being read by machines, the barcode and address must be in the right format.

Using a CASS-certified vendor can save you more than just a small postage discount, however. It can save you thousands by preventing failed deliveries.

A 2021 report, Valuing Home Delivery Review, by IMRG, the UK’s top online retail association, put the cost of failed parcel deliveries in the UK at £1.2 billion—or 1.7 billion US dollars.

Another study by Convey, a US-based delivery management vendor, revealed that 87% of consumers expect brands to make amends when they miss a delivery date and 52% expect a refund or discount on shipping costs.

Don’t let undelivered packages or re-delivery fees eat into your profits! Make sure your address validator is using CASS-certified address matching methods.

What Is NCOA Certification?

USPS NCOA Certified

NCOALink or NCOA (National Change of Address) is a data set containing approximately 160 million permanent change-of-address records filed with the USPS in the last 48 months. This list consists of names and addresses of individuals, families, and businesses who have filed a change of address.

To become NCOA certified, or licensed, you must be using CASS-certified address matching software with the NCOALink process.

There are six (6) licensing categories with license fees ranging from $1,350 to $230,000.

Interface Developer
Interface Distributor
Full Service Provider (FSP)
Limited Service Provider (LSP)
End User Mailer (EUM)
NCOALink® MPE Solution

Unlike the CASS certification process, NCOA certification requires software developers and mailers to supply a great deal more information, including:

Application
Confidentiality Statement
Self-Certification Statement
Key Personnel Listing
Web Access Request Form
Security Documentation

CASS vs NCOA What is the Difference?

Sometimes addresses change. That might be because a house address was changed from an even number to odd, or it might be because your friend has decided to become a digital nomad and work from Bali for the next 3 months.

You’re probably wondering why a house number would be changed from even to odd. Everyone knows that even numbered addresses are on one side of the street and odd numbered addresses are on the other, right? Well, address assignments weren’t always that standardized!

Local governments used to assign addresses however they wanted, but that made it difficult for emergency services to find the right location. Hence, address standardization—building numbers originating from central locations, the evens and odds on separate sides of the street, etc. Old addresses were updated, changing them to meet the new standards.

LACS was established by 911 to keep track of all those changes. This, plus DPV, forms the backbone of CASS-certified address validation.

Now, for the second example, if your digital nomad friend is very responsible, he or she will visit any USPS location or the Official USPS Change-of-Address website and fill out the form to get their mail forwarded to their new address. This will add their information to the National Change of Address (NCOA) database.

So, if you want to do a direct mail promotion and blanket a zip code with coupons for your new Crumbl franchise and you don’t want to waste money on outdated or incomplete addresses, you want to use a CASS-certified address validation software.

If you want to make sure your annual Shark Week party invitations are getting to the right people, you better hope their current address and not an outdated address is in the NCOA database. However, the NCOA database does come with some limitations...

NCOA Address Validation Disadvantages

NCOA is great for the USPS, but not always so great for consumers.

When bulk mailing customers use NCOA, it helps the USPS reduce non-deliverable mail and prevent re-mailings because the address correction is applied prior to the mailing. Cutting down on undeliverable mail and re-deliveries also improves overall postal service speed and accuracy.

However, NCOA has more limited information than CASS. If there's no name, it doesn't work. If there's no address, it doesn't work. The data is limited to the past four years and relies on people voluntarily filling out a change of address form, which fewer and fewer people are doing these days.

It’s also extremely expensive for providers to become licensed to use NCOALink (costs that inevitably get passed on to their customers) and the USPS requires a lot of personal data about each customer who wants to process their list using NCOALink.

But the biggest reason why SmartyStreets chooses to offer CASS processing and not use NCOA is that the USPS requirements state that the minimum number of addresses that can be processed at one time is one hundred.

Most of our customers are companies that are using raw data, not mailing lists. For example, a credit card company might need to validate a single address at time, to confirm this is the right address for Bob Smith at One Hundred Main Street in New York, New York. They want to be able to test that address prior to generating a shipping label to determine if it’s the most recent address. You can’t do that with NCOA. You have to process an entire list.

While we did offer NCOALink previously, we found it was not providing the performance or value that our customers wanted or expected. We focus on making sure our services provide three things: speed, reliability, and ease of use. NCOA just wasn’t checking off all our boxes.

PSST—You can test out our CASS-certified address validation services on a single address for FREE right here.

We also offer bulk address validation for lists, address validation APIs, and geocoding. Learn more.

The leader in location data intelligence

Ready to get started?