Scouting Your Customer Data: What NCOA Return Codes Are Really Telling You

Written by Brooks Hall
CEO, Brooks Integrated Marketing • Founder of FreeNCOA

“Most marketers look at an NCOA report to see what changed. We look at it to understand what it means for the next marketing campaign.”

Before You Build Anything, Scout the Terrain. One of my favorite memories is helping my son complete his Eagle Scout project.

He decided to build a beautiful wooden arbor for a local church. The arbor would eventually be covered with climbing plants to help hide several large air conditioning units. Like most Eagle Scout projects, it looked pretty straightforward on paper.

Until we actually visited the site. Before we bought a single board or dug the first post hole, we walked the property together. We measured. We checked the slope. We looked at drainage. We discussed where people would walk and how the plants would eventually grow.

I remember joking with him that we had spent more time “scouting” than building. But that’s exactly what good Scouts do. They gather information before making decisions. Customer databases deserve the same treatment. Far too many organizations are eager to launch their next marketing campaign. They print the mail pieces, schedule the emails, and load the call lists without first taking a close look at the quality of the customer data they’re relying on.

That is exactly what NCOA processing helps you do. The USPS National Change of Address (NCOALink®) database doesn’t simply tell you who moved. It gives you valuable clues about the health of your customer database and, in many cases, about the quality of the data sources feeding it.

In other words…

NCOA helps you scout your customer data before you invest thousands of dollars marketing to it.

Data Hygiene Is More Than Cleaning Addresses

When people hear the term data hygiene, they often think about fixing spelling mistakes or updating mailing addresses. That is certainly part of it.

But good data hygiene is really about answering one simple question: “Can I trust the data I’m about to market to?”

Every customer record tells a story. Some customers moved. Some never updated their forwarding address. Some addresses became vacant. Some apartment numbers are missing. Some records have been sitting untouched for years. The challenge isn’t simply identifying those records. The challenge is knowing what to do next. That is where NCOA return codes become incredibly valuable. Every return code provides another clue about your database. Think of them as little trail markers guiding you toward better marketing decisions.

Most People Read the Codes…

Many organizations process an NCOA file and immediately ask one question:

“How many addresses changed?”

That’s useful. But after processing millions of customer records since launching FreeNCOA in 2009, we’ve learned that the most valuable information isn’t just what changed. It’s why it changed. And more importantly…

What should you do next?

For example:

• Did customers move faster than normal?
• Are certain acquisition sources producing poorer-quality data?
• Has one vendor’s data started aging faster?
• Are apartment numbers consistently missing?
• Is one marketing channel collecting incomplete addresses?
• Are duplicate records increasing?

Those questions tell you far more about the future success of your marketing campaigns than simply counting how many people moved.

NCOA Doesn’t Just Evaluate Customers…

It Evaluates Your Data Sources

This is one of the biggest lessons we’ve learned over the years. Every marketing database has a history. Some records came from your website. Others came from purchased lists. Some came from trade shows. Others came from customer referrals or previous marketing campaigns. As those records age, patterns begin to emerge.

One list may produce an unusually high number of:

• Vacant addresses
• Moved Left No Address (MLNA)
• Foreign moves
• Missing apartment numbers
• Address corrections
• Undeliverable records

Those aren’t just NCOA results. They’re feedback about your data collection process. Sometimes the problem isn’t your marketing. Sometimes it’s the source feeding your CRM. One outdated vendor. One aging acquisition campaign. One imported customer list. Your NCOA results often reveal those issues months before declining campaign performance makes them obvious. That’s why we encourage clients to compare NCOA trends from one campaign to the next. When your return codes begin changing, your data quality may be changing too.

Where PCOA Fits Into the Picture

NCOA answers one important question: “Did the USPS receive a forwarding address?”

PCOA answers a different question. “Is this individual still associated with this address?”

Those are two completely different things. Someone may not have filed a USPS forwarding request. That doesn’t necessarily mean they still live there. Conversely, someone may still receive mail at an address even though another family member moved. That’s why we recommend looking at both NCOA and PCOA together whenever possible. NCOA helps identify official USPS moves.

PCOA helps confirm the relationship between the individual and the address. Together, they provide a much more complete picture of customer data quality. Instead of simply updating addresses, you’re evaluating the overall health of your customer database before launching your next campaign.

The Return Codes That Matter Most

One mistake I see quite often is people trying to memorize every NCOA return code. There are dozens of them. You don’t need to memorize them. Instead, group them into simple business questions.

When reviewing an NCOA report, I generally ask four questions:

1. Can I Mail This Record?

These are your address quality indicators.

Examples include:

• DPV Y
• DPV D
• DPV S
• DPV N
• Vacant
• NoStats

These codes tell you whether the USPS believes an address is deliverable and whether additional attention is needed before mailing. The DPV field contains several positions that indicate delivery confirmation, vacancy, and other address characteristics that help determine mailing readiness.

2. Did This Customer Move?

Examples include:

• A
• 01
• 02
• 03
• 91
• 92

These codes indicate different types of move activity, including successful forwarding, foreign moves, moved-left-no-address (MLNA), closed post office boxes, and secondary address changes.

3. Is My Data Source Aging?

If you’re consistently seeing:

• Address corrections
• Missing apartment numbers
• Vacant addresses
• MLNA records
• ANKLink matches

your customer acquisition process may need attention.

4. What Should We Do Before the Next Campaign?

This is where data hygiene becomes marketing strategy.

Instead of simply updating records, you’re deciding:

• Which records should be mailed
• Which should be suppressed
• Which need additional verification
• Which require PCOA confirmation
• Which data sources deserve closer inspection

That is where NCOA becomes much more than a postal requirement. It becomes a business intelligence tool.

Reading Between the Lines: What Your NCOA Codes Are Really Saying

One thing I’ve learned after processing millions of customer records is that the USPS doesn’t just return codes. It returns clues. Every code tells you something about your customer, your database, or your marketing process. Some are green lights. Some are yellow lights. Some are warning signs that deserve immediate attention.

Let’s walk through the ones I believe matter most.

Green Light Codes: Keep Moving Forward

These are the codes that tell me the database is generally healthy.

DPV Y — Deliverable Address

This is one of my favorite codes to see.

A DPV Y indicates the USPS confirmed both the primary address and, when applicable, the secondary address (such as an apartment or suite number). In plain English, it’s a strong indicator that the address is deliverable.

For marketers, that means:

• Good candidate for direct mail
• Strong deliverability
• Little additional investigation needed

It doesn’t guarantee your customer still lives there—but it tells you the address itself is valid.

NCOA Code A — New Address Found

This is exactly what NCOA was designed to do. Code A means the record matched a USPS change-of-address record and a new address was returned. Instead of celebrating that someone moved, I encourage clients to celebrate something else. You didn’t lose the customer. You found them again.

LACSLink Matches

Occasionally addresses change because municipalities rename streets or convert rural route addresses into city-style addresses.

LACSLink keeps your database aligned with those official changes, helping maintain deliverability without requiring your customer to do anything.

Yellow Light Codes: Investigate Before Mailing

These records often can be salvaged, but they deserve a closer look.

DPV D and DPV S

These codes indicate the primary address validated, but there is an issue with the secondary information. The apartment, suite, or unit may be missing or could not be confirmed. If you’re mailing apartments, senior living communities, or commercial buildings, this matters. A missing suite number can easily become an undeliverable mail piece.

Unit Missing

One of the most common warning codes we see is:

Unit Missing – That usually tells me the customer exists. The building exists. The address exists. But your CRM failed to capture one important detail. Sometimes this isn’t a mailing problem at all. It’s a data collection problem. Maybe a web form didn’t require apartment numbers. Maybe a call center representative skipped the field.

Those small process improvements often produce surprisingly large improvements in deliverability.

ZIP Changed

When the USPS changes the ZIP Code or ZIP+4, it’s doing you a favor. Rather than viewing this as an error, I look at it as free data quality improvement. The address has been standardized to USPS specifications, making future mailings more accurate.

Red Light Codes: Stop and Investigate

These are the codes that tell me something larger may be happening.

MLNA (Moved Left No Address)

This is one of the biggest warning signs in direct mail. The USPS knows the individual moved. Unfortunately, they never filed a forwarding address. Mailing these records usually creates unnecessary waste.

Instead, I recommend:

• Suppressing the record temporarily
• Looking for alternate contact methods
• Confirming occupancy with PCOA before future mailings

Foreign Move

Sometimes customers leave the United States entirely. If your organization only markets domestically, this is usually a suppression candidate. Again, the important thing isn’t the code. It’s what you do with it.

Vacant Addresses

A vacant flag means the USPS considers the address vacant. In many cases, this indicates the property has not been occupied for an extended period. Whenever I see vacancy rates increasing across a customer file, I immediately start asking questions. Did this campaign use an older data source? Did we purchase aged records? Has this database simply gone too long without maintenance?

ANKLink 77

One of the most overlooked codes is ANKLink 77.

This identifies records found in the USPS 19–48 month change-of-address window. The layout guide recommends suppressing or deleting these records rather than continuing to mail them.

For marketers, this is valuable because it tells you the database is aging beyond the traditional NCOALink timeframe.

The Codes Tell You About More Than Customers

Here’s something I don’t think enough people talk about. Sometimes your NCOA report isn’t exposing customer behavior. It’s exposing vendor behavior. Let’s imagine two customer acquisition campaigns.

Campaign A

• 2% Vacant
• 1% MLNA
• Few corrections

Campaign B

• 8% Vacant
• 6% MLNA
• Hundreds of address corrections

Which campaign would you invest in next year? Your NCOA report just answered the question.

That’s why I often tell clients:

Your NCOA report is one of the best scorecards you’ll ever receive for evaluating data quality.

Why We Also Recommend PCOA

One of the reasons we developed PCOA was because NCOA only answers one question. Did the USPS receive a forwarding address? Marketing teams usually need a second answer.

Is this person still associated with this address?

PCOA helps confirm the relationship between the name and the address, providing another layer of confidence before investing in printing, postage, or digital marketing. When combined, NCOA and PCOA help you understand not only what changed—but whether your underlying customer data is still trustworthy.

Frequently Asked Questions

What do NCOA return codes mean?

NCOA return codes describe what happened when a record was compared against the USPS change-of-address database. They can indicate moves, forwarding addresses, missing information, or reasons why no match occurred.

What does DPV Y mean?

DPV Y means the USPS confirmed the address as deliverable, including both the primary address and any required secondary information.

What does MLNA mean?

MLNA stands for Moved Left No Address. The USPS knows the individual moved but does not have a forwarding address available.

What is ANKLink 77?

ANKLink 77 identifies individuals who moved between 19 and 48 months ago. These records are generally good candidates for suppression because they are outside the standard NCOALink processing window.

What is the difference between NCOA and PCOA?

NCOA identifies official USPS change-of-address records.

PCOA helps confirm whether the individual is still associated with an address.

Together they provide a more complete picture of customer data quality.

Final Thoughts

Helping my son build his Eagle Scout project reminded me that preparation is rarely the most exciting part of a project.

But it’s almost always the most important.

The same is true with customer data. Before you invest in printing. Before you launch another email. Before you send your sales team into the field, scout your data.Your NCOA report isn’t just showing you who moved. It’s telling you where your customer database is healthy. Where it’s beginning to age. Where your data sources may be slipping. And where your next marketing campaign can become significantly more effective.

Because after sixteen years of helping organizations improve customer data, I’ve learned one thing:

The best marketing campaigns don’t start with better creative. They start with better data.

Ready to Scout Your Customer Data?

Whether you’re preparing your next direct mail campaign, evaluating a new data source, or simply trying to improve the quality of your customer database, FreeNCOA can help.

Run your file through NCOA, review the return codes, and use those insights to make smarter marketing decisions before you spend your next marketing dollar.

Better Data. Smarter Marketing. Better Results.

NCOA Processing, PCOA processing