National Change of Address (NCOA): How List Updates Work
Short answer
National Change of Address (NCOA) is the USPS file of permanent change-of-address requests, about 160 million records. Mailers do not get the file itself; they run their lists through licensed NCOALink providers, who return new addresses for people and businesses that moved within the last 18 or 48 months, depending on the licence.
When someone moves in the US and files a change-of-address request, USPS forwards their mail for a while. Your business does not find out. Your CRM still has the old address, your next letter gets forwarded or returned, and eventually forwarding ends. National Change of Address processing is how you find out before that happens.
USPS describes the NCOALink product as a secure dataset of approximately 160 million permanent change-of-address records. You never see it. You send your list through a licensed provider, and it comes back with new addresses where a match was found.
Why moves are the biggest source of bad addresses
The USPS Office of Inspector General looked at undeliverable-as-addressed mail in a 2015 report. Based on a 2006 joint study, it attributed about 40 percent of such mail to the public, 35 percent to business mailers and 23 percent to USPS itself. Most of the public share is moving:
Shares of the public-caused portion (39.5 % of all UAA mail).
Source: USPS OIG report MS-MA-15-006 (2015), citing a 2006 MMA study
The study marks the three highlighted reasons as customers who moved without filing a change of address. NCOA cannot help with those. The same OIG report notes that as many as 40 percent of people who move do not inform the Postal Service. On the mailer side, the same table lists “forwarding time expired” at 15.8 percent: the customer did file, USPS forwarded for a while, and the mailer never updated the list. That is exactly the case NCOA processing fixes.
How NCOALink processing works
- ExportNames and addresses, one record per person or business, with a customer ID.
- StandardiseThe provider runs CASS-certified software so addresses match the USPS format.
- MatchName and old address are compared with change-of-address records.
- Return codesNew address, move date, move type (individual, family, business) or a flag such as moved, left no address.
- UpdateYou write the new address back to the CRM and keep the old one in history.
Matching is by name and address, not by address alone. Family moves and individual moves are different records. If your list has J SMITH at an address where Jane Smith filed an individual change of address, the provider’s matching logic decides whether that counts. Clean names before processing; it is one of the few levers on your side.
The returned file usually tells you more than the new address. Flags such as “moved, left no address” or “PO box closed” are just as valuable, because they tell you to stop mailing that record. Our article on address deduplication is the natural next step: after a move update, duplicates often surface where a customer exists once under the old and once under the new address.
Decide in advance what your systems do with each result. New addresses should replace the old one in the shipping fields, while the old address moves to a history table with the move date; finance and support teams sometimes need it. Records flagged “moved, left no address” should stop getting marketing mail, but do not delete the customer, who may still order online. Business moves deserve a human look, because a company’s new address can also mean a new contact person. And keep the provider’s return file for a while. When a customer later disputes an address change, it is your only record of where the update came from.
Licence types: 18 or 48 months
USPS licenses NCOALink in six categories. Three of them are relevant to most businesses, and they differ in how much history they get and how fresh it is. The figures below come from the USPS NCOALink page on PostalPro.
| Licence | Months of move data | Updates from USPS | Annual fee |
|---|---|---|---|
| Full Service Provider | 48 | Weekly | $436,300 |
| Limited Service Provider | 18 | Weekly | $36,440 |
| End User Mailer | 18 | Monthly | $17,840 |
Full and Limited Service Providers process lists for clients. End User Mailers may process only their own house files, not lists for related companies or third parties. All licensees must use CASS-certified address matching software.
For most businesses the arithmetic is simple. Unless you mail millions of pieces and want processing in-house, buying runs from a provider is far cheaper than a licence. The choice that matters is 18 versus 48 months. If your list has not been updated for two years, an 18-month run misses everyone who moved before that window.
Move Update and the 95-day rule
For US mailers, there is also a compliance side. USPS rules for presorted and automation-priced First-Class and Marketing Mail have long required that addresses be updated for moves within 95 days before the mailing. NCOALink is one of the accepted methods; the Address Correction Service, which sends notices when mail meets a forwarding order, is another. USPS checks compliance and can assess charges on mailings that fail; Notice 123 lists a Move Update assessment charge of 8 cents per piece.
Even if you only ship parcels and never send bulk mail, the logic holds: an address that was right a year ago is not necessarily right now.
Outside the US
Other postal operators run comparable services, built from their own forwarding data. Germany’s equivalent is Deutsche Post’s POSTADRESS MOVE database, which draws on mail forwarding orders where the mover agreed to the data being used for address updates. Deutsche Post says it holds more than five million current moves from the last 24 months and that about 22,000 consumers and businesses move in Germany every day. Its partner database adds more than 22 million historical moves.
The principle is the same everywhere: the post office knows about the move because the customer asked for forwarding. The legal basis differs by country; Deutsche Post builds its product on the mover’s consent.
Putting move updates on a schedule
Moves happen continuously, so a single cleanse decays. For active customer lists, a sensible rhythm is a full NCOA run before every large mailing and at least once a quarter, plus electronic address correction notices on everything you mail in between. The cost of not doing it shows up as returned mail and carrier fees; see address correction fees for the parcel side.
At the point of entry, keep validating new addresses so that the records you update are clean in the first place; the three levels of address verification explain what to check. Teams that run move updates, deduplication and validation across several systems end up building a small data platform, which is the kind of work OnlineBuilders does.
If you have never run one, ask an NCOALink provider for a 48-month test run on a sample of 10,000 records, and compare the move rate it reports with your current return rate.
Address format checker: Checks postcode format, house number and line order against the postal rules of the selected country, and prints the address in the format the post expects.
Questions people ask
Can I buy the NCOA database directly?
Only by becoming a licensee, which requires USPS certification and an annual fee. Most businesses instead send their list to a Full Service or Limited Service Provider, who processes it and returns the updated addresses.
What is the difference between 18-month and 48-month NCOA?
USPS gives Full Service Providers 48 months of change-of-address data, while Limited Service Providers and End User Mailers get 18 months. A 48-month run finds older moves, which matters for lists that have not been updated in years.
Does NCOA find people who moved without telling the post office?
No. NCOA only contains moves for which a change-of-address request was filed. People who move without filing one stay at their old address in your list until mail comes back.
How often should I run NCOA processing?
Before every large mailing, or at least quarterly for active customer lists. USPS rules for discounted commercial mail have long required a move update within 95 days before mailing.
