Every year, roughly 40 million Americans file a change of address with the United States Postal Service. That means if you are mailing to a list that has not been updated recently, a meaningful chunk of your pieces are going to the wrong address. They will either be returned, forwarded with delay, or discarded entirely.
NCOA processing solves this problem by matching your mailing list against the USPS National Change of Address database before you mail. It is one of the simplest ways to improve deliverability, reduce waste, and protect your campaign ROI.
How NCOA Processing Works
The USPS maintains an 18-month rolling database of every permanent change of address filed by individuals and businesses. When you submit your mailing list for NCOA processing, each record is compared against this database. If a match is found, the old address is replaced with the new one.
The process is straightforward:
- You submit your mailing file (names and addresses) to an NCOA-licensed processor.
- The processor runs your records against the USPS NCOALink database.
- Matched records are updated with the current address.
- You receive the cleaned file along with a summary report showing how many records were updated, how many had no match, and how many were flagged for other issues.
The entire process typically takes a few hours for most file sizes, and many providers can turn it around within 24 hours.
NCOA vs. ACS: Understanding the Difference
Some mailers confuse NCOA with ACS (Address Change Service). They serve different purposes. NCOA is a pre-mailing process — you clean your list before you print and mail. ACS is a post-mailing service where the USPS sends you electronic notifications when a mail piece is forwarded or returned. Both are useful, but NCOA prevents the problem while ACS reports on it after the fact.
For maximum deliverability, use NCOA before every mailing and ACS as an ongoing feedback loop to catch changes between NCOA runs.
When NCOA Processing Is Required
If you mail at presort or automation rates through the USPS, you are required to process your list through NCOA (or an equivalent Move Update method) within 95 days of your mailing date. This is not optional — it is a USPS regulation that applies to all Standard Mail and First-Class presort mailings.
Failure to comply can result in your mailing being rejected at the post office or losing your postal discount, which on a large mailing can cost thousands of dollars.
Even if you are not mailing at presort rates, NCOA processing is still a best practice. Every undeliverable piece is money wasted on printing, postage, and opportunity cost.
What Happens When You Skip NCOA
The math is simple. If 10% of your list has moved and you mail 50,000 pieces, that is 5,000 pieces going to the wrong address. At a fully loaded cost of $0.50 per piece (data, print, postage), you just wasted $2,500. And that does not account for the lost revenue from 5,000 prospects who never saw your offer.
Over multiple mailings per year, the cost of skipping NCOA compounds rapidly. Most NCOA processing services charge between $0.005 and $0.02 per record — a fraction of the cost of a single undeliverable mail piece.
NCOA and CASS: Better Together
NCOA processing is often paired with CASS (Coding Accuracy Support System) certification. While NCOA updates addresses that have changed, CASS standardizes your addresses to match USPS formatting, adds ZIP+4 codes, verifies deliverability, and qualifies your mailing for postal discounts.
Together, NCOA and CASS ensure that:
- Addresses are current (NCOA)
- Addresses are formatted correctly (CASS)
- You qualify for the lowest available postage rates (CASS)
- Undeliverable addresses are flagged before you print (both)
Most data providers and mail houses offer NCOA and CASS as a bundled service. If yours does not, ask why.
How Often Should You Run NCOA?
At minimum, run NCOA processing before every mailing. If you mail frequently (monthly or more), process your master file at least quarterly. If you mail seasonally, process before each campaign.
For house files (your own customer database), run NCOA at least every 90 days to stay within the USPS 95-day requirement and keep your data fresh for all customer communications, not just direct mail.
Choosing an NCOA Provider
Not every data company is licensed to run NCOA processing. The USPS licenses specific service providers through its NCOALink program. When choosing a provider, confirm that they are an authorized NCOALink Full Service Provider or work directly with one. Ask about turnaround time, pricing per record, and whether they include CASS certification in the same pass.
A good NCOA provider will also flag records that cannot be updated — such as addresses where the forwarding order has expired (older than 18 months) or where the individual filed a "do not forward" request. These flags help you decide which records to suppress from your mailing and which to investigate further.
The Bottom Line
NCOA processing is not an optional step in direct mail — it is a foundational one. It reduces waste, improves response rates, satisfies USPS requirements, and pays for itself many times over on every campaign. If your current data provider does not include NCOA processing as a standard part of their service, it is time to find one who does.