If you’re in business, you likely have at least one mailing list, and possibly many marketing lists. Your direct mail marketing lists may come from active and former customers, shipped orders or invoices for services, trade show inquiries, incoming web form leads and other sales prospects from a CRM, webinar attendee lists, or other sources. No matter where they come from, these “house names” should be pretty valuable to you—but they won’t be worth much if they’re not verified as current addresses.
Note: This post is about the steps required to maintain your own in-house mail marketing lists. If you rent or buy a list, all of these rules still apply, however the list owner or compiler should be performing these important list hygiene processes for you to ensure that your investment is as current and as deliverable as it can possibly be. Some may charge extra for these list services, some will include it in the purchase price.
How do I know if my mail marketing lists need an update?
If you’re asking, your marketing lists probably haven’t had maintenance in a while, and you likely need to do some cleanup. No judgement here, by the way—this is a common problem for marketers and if it’s not a part of your maintenance schedule, or if you mail infrequently, it’s easy for your marketing lists to get away from you.
Instinct shouldn’t be your only guide, however. Technically, to qualify for USPS bulk mailing rates you are required to update your marketing lists within 95 days before a mailing date. So, that’s the general rule, however people who mail frequently in high volumes may choose to update their lists every month, because the savings on undeliverable mail can be much higher than the cost of the list maintenance service.
Why is it necessary to update my mailing lists for business?
Good question. In the U.S. there are 86 address changes every minute of every day throughout the year (which adds up to about 45 million moves per year). Here’s another way to think of it—about 14% of the population moves every year. That’s a lot of address changes, and a lot of potentially undeliverable mail and waste.
In addition to the obvious challenges of a free-moving public, incomplete or missing business suite or apartment numbers can also hamper the delivery of your mail. What about when people die, go to nursing homes, or even prison? It’s a sad thought, but it’s a reality of life. List maintenance can tidy all of these things up.
And you can’t rule out human error, either, as team members make manual additions to customer and prospect lists when new business comes in. Getting the best postage rates for mail is all about standardization and deliverability. So, “address cleansing” is the name of the game.
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There are five reasons why address cleansing is essential for mailing:
- To format all addresses in compliance with USPS rules for standardization
- To correct address information and maximize deliverability
- To identify, and remove or update undeliverable addresses before printing
- To update the addresses of mail recipients who have moved
- To eliminate wasteful, duplicate entries from the direct mailing list
Bad list data is not only a waste of postage and materials, but also a lost opportunity to get a return on your investment. The USPS reports that last year there were billions of pieces of undeliverable as addressed (UAA) mail – in fact, about 4% of all mail was undeliverable. The USPS estimates the cost to businesses at over $20 billion annually. Sadly, most of this waste is preventable with a small amount of effort.
Want to learn more about Undeliverable as Addressed (UAA) mail? Watch this video.
Managing your own direct mail marketing lists:
The cleansing of your data ensures deliverability and the best postage rates. Many print service providers offer help in this area, often calling it “List Services.” You can also run the maintenance yourself. There are some really good cloud-based list cleansing services out there—my favorite is AccuZIP’s pay-as-you-go model, but you can also find self-service list cleansing at Melissa Data, Experian (although gated), and others.
So, you know you need to do some maintenance on your marketing lists, but what’s the protocol? Here’s the run-down of what services need to be done to maintain a healthy list:
Standardize all of the addresses:
The first critical list service is called CASS certification, and the acronym stands for Coding Accuracy Support System. This service is designed to format addresses to standard postal addressing requirements, and to identify addresses that will be undeliverable.
A non-standard address may be deliverable, however it does not comply with USPS specifications for abbreviation and format. A standardized address includes all required components of a deliverable address as specified by the USPS and uses the proper USPS standardized abbreviations.
A complete address has all of the address elements necessary to allow an exact match with the most current USPS Zip+4 file plus the IMb™ to obtain the finest level of detail for the delivery address. Use the search term “USPS Publication 28” to view the official USPS Postal Addressing Standards document.
Addressing Your Mail Marketing Lists (the right way)

CASS certification will determine the validity of an address and standardize it, but what it does NOT do is determine whether the occupant is still living there—which leads us to the next critical address service.
Determine if the individual or business is still at the address:
The USPS National Change of Address database (NCOALINK®) is a secure dataset of approximately 160 million permanent change-of-address records going back 4 years. The list consists of the names and addresses of individuals, families and businesses who have filed a change-of-address forms with the USPS.
The one caveat with NCOALINK is that only about 60% of individuals and businesses who move actually notify the USPS about their new address (sometimes even deliberately to avoid creditors). Yikes. If that’s the case, then the NCOALINK database won’t catch the people who don’t file a form.
Pro Tip: AccuZIP’s ACOA service goes way beyond the NCOALINK database, providing 20-40% more matches than running the NCOALINK alone. Where do the matches come from? They cross-reference compiled databases from credit cards, retail, utility companies, and more. Full disclosure, AccuZIP is a Foldfactory sponsor, but I accept their sponsorship because I believe in their products. This is not an affiliate link.
Eliminate Duplicates and Near-Duplicates (also called merge-purge):
A low-lying problem common to direct mailing lists for business is the duplicate entry. Exact duplicates are easy to identify and remove using de-duping software, however the near-duplicate can be too subjective for the software to pick up. Near-duplicates, like duplicate addresses with slightly different spelling of the addressee’s first name, can be problematic not only from the standpoint of the resources that are wasted on materials and postage, but having near-duplicates in your database also throws off your internal counts and ROI figures.
Even worse, sending duplicate mail to a customer can destroy your relationship with them—they may feel that you’re outdated, wasteful and inefficient. So, take a very close look at the list, have it de-duped, and you may want to have a more sophisticated data scrub performed to get rid of near-duplicates as well.
Want to learn more about Duplicates and Near Duplicates? Watch this video.
Identify and remove addresses that should NOT be receiving mail:
There are some addresses that are legitimate mailing addresses that you should not be mailing to (but you don’t know it). For example, you can eliminate people on the Do Not Mail list, the deceased, and even prison and nursing home occupants. This is called Address Suppression service, and it flags for removal these difficult-to-identify addresses.
Find missing or incorrect apartment and suite numbers and fix them:
Lots of addresses are undeliverable due to incorrect or incomplete addresses—and one of the biggest issues is when addresses have incorrect or missing apartment or business suite numbers in them. The list service to correct this problem is called Apartment Append service. Pro Tip #2: Any Apartment Append service you use should state clearly that they use only DPV-verified (USPS Delivery Point Verified) addresses.
Improve your internal marketing list maintenance procedures:
You will need to establish good list maintenance procedures in your company, setting a rule that no address will be added to the mailing list unless it’s been standardized and verified. You could keep a list on the side of new addresses to run address cleansing on as a small batch, or just be mindful of what is added and make sure that the list is run through the list services above before they’re used. It’s hard to break old habits and get everyone to change their process, but without good practices, your squeaky-clean list can revert right back to its outdated format in no time.
List Maintenance FAQs:
Where should I start? What is the most important thing to be concerned with?
The first thing to do is to get your arms around your marketing lists. Pull them together and just be honest about where you are with them. Your marketing lists might be a mess. Or they might not be too bad. Do a first pass visual search and review to try to find the obvious issues that you can control. Once you know what you have, you’ll need to decide if you want to do your own hygiene (not as hard as it sounds), or if you want someone else to do it for you.
I don’t want to do this myself – who can help me?
You can always ask your printer or mail services company for help with updating your marketing lists. This is generally called “List Services” and usually would involve a service charge. There are also several cloud-based list services companies that you can hire to do it for you. It all comes down to who you feel comfortable with.
Can I perform my own marketing lists hygiene? If so, what software should I use, and how often?
The quality of address cleansing can vary based on the software, so do your research first. No time for research? For a high-quality list cleansing service, visit the AccuZIP Pay-As-You-Go portal, upload your list and it’ll run through their data quality and enhancement services, which includes CASS, NCOALINK,AccuZIP ACOA, Duplicate Removal, Deceased List Suppression, Apartment Append, and more. It’s fast and affordably priced. You’ll want to do this every 90 days.
While you’re there, you can move right to the next step—mailing! AccuZIP6 bulk mail postal software will take your standardized, clean list and presort it, so that you can qualify for the lowest possible postage rates. It’ll also help you print Intelligent Mail® Barcodes with your new, standardized addresses on all of your mailpieces, and you can do all of this, and more, right in one program.
Is there a service that can “enhance” the list I have, adding in phone numbers, emails,* or demographic information?
Yes, list services companies are generally able to append phone numbers, email addresses, and other very valuable demographic data elements including but not limited to age, income, renter/owner, occupation and hobbies. This information can be useful in determining the potential of a file for segmentation, modeling, and other analytic applications, and will give you the option of integrating additional marketing channels into their campaign to fine tune your strategic planning. Contact your list vendor, such as AccuZIP, for custom quotes.
*An important note about emails: the subject of purchasing emails sends up a lot of red flags for marketers, as it should. You have to be very careful in this territory. Platforms like Mailchimp and Constant Contact in their terms of use do not allow the sending of emails from purchased or rented marketing lists. Your bulk emails will probably bounce or get sent to SPAM folders—and you’ll also likely be kicked off the platform.
With that said, it’s important to note that email address information is largely self-reported to the sources that compilers aggregate from, so if the email address is deliverable and valid when they ping it, they might have the ability to include it in the database by request—but what can you do with a bunch of emails you can’t send?
Often email can be used to match individuals to their social media accounts for integrated marketing campaigns. There are also CAN-SPAM compliant subscriber acquisition platforms that ensure the bulk email messages are delivered to “warm up” the contacts for you—one example of this type of service is MailClickConvert. I haven’t used it personally, but some companies have had success with these types of services.
Get Your Arms Around Your Marketing Lists and Get Started
So, are you ready to get started? I thought so! Get your arms around the marketing lists you have—in whatever shape and form they’re in—because there’s no shame in acknowledging that you have outdated lists. We’re going to deal with it and whip them into shape. Easiest thing to do is to visit the AccuZIP Pay-As-You-Go portal, and upload your list for instant, high-quality list cleansing at a very reasonable price.
And although it probably seems like there’s a lot to do to keep your lists squeaky clean and in their most deliverable state, remember that most of these processes are done in sequence through some pretty sophisticated software programs. It’s not as though YOU have to figure out and correct the issues line by line. You just need to gather your marketing lists, and upload or send them to a list services company you trust. Make a habit out of it, and you’ll be feeling better about your mailing lists in no time!
If you would like more information on how to create a mailing list, check out my blog on How to Get the Right Direct Mail Marketing List to Grow Your Business.