Frequently Asked Questions (FAQs)

Have questions about address tools, USPS standards, or how to build a complete address data quality strategy? Start here for concise answers to our most frequently asked questions.

FAQs on Address Data Quality Importance

1. What is the estimated annual cost of Undeliverable-As-Addressed (UAA) mail to the mailing industry?
   • • Undeliverable-As-Addressed (UAA) mail costs the mailing industry over $20 billion annually. The article highlights that this amount is wasted on mail that never reaches its intended destination.

2. What is the difference between an address that is “perfect” for USPS postage discounts and one that is “perfect” for comprehensive business operations?
   • • The USPS considers an address perfect if it is Complete, Correct, and Current for delivery and postage discounts. However, a truly perfect address for business purposes must also be:

• • • • Connected: A good name/address combination for the intended recipient.
      • Credible: Verified from a fraud risk perspective.
      • Compliant: Meets industry-specific regulations (e.g., Bank Secrecy Act for financial institutions).

3. What is USPS Publication 28 and why is it important for mailers?
   • • USPS Publication 28, formally titled “Postal Addressing Standards,” is the definitive reference for how addresses should be formatted, structured, and validated in the United States. It is important because:

• • • • It is mandatory to follow its standards to qualify for USPS automation and presort discounts.
      • It explains the structure, logic, and reasoning behind address standards, which is crucial for data collection, database design, and troubleshooting delivery issues.

4. What is CASS™ and does it certify mailers?
   • • CASS™ stands for the Coding Accuracy Support System. It is a USPS certification program for the software that processes addresses, not the mailers themselves. CASS™-certified software has been approved by the USPS to standardize addresses, assign correct ZIP codes and carrier routes, and validate delivery points (DPV®).

5. What is the primary purpose of NCOALink® and what regulatory requirement does it help mailers meet?
   • • NCOALink® (National Change of Address Link) matches a mailing list against the USPS database of change-of-address orders to update records before mailing. It is the primary pre-mailing solution used to meet the Move Update requirement, which is mandatory for First-Class Mail and Marketing Mail seeking automation discounts.

Learn more here.

FAQs on Pub 28 Content

1. What is the formal title and primary purpose of USPS Publication 28?
   • • The formal title is “Postal Addressing Standards.” Its primary purpose is to serve as the definitive reference for how addresses should be formatted, structured, and validated in the United States, acting as the foundation for every USPS discount and automation process.

2. Why is understanding Pub 28 essential for mailers?
   • • Understanding Pub 28 is essential because all USPS automation and presort discounts are built on its standards, making compliance mandatory for discount eligibility. Beyond discounts, it provides the structure, logic, and reasoning behind address standards, which is necessary for data collection, database design, and troubleshooting delivery issues.

3. What are some of the core Address Information System Products and Services documented in Pub 28?
   • • The publication documents 13 official products and services. Core offerings include:

• • • • ACS™ (Address Change Service): Provides feedback about undeliverable mail.
      • CASS™ (Coding Accuracy Support System): Validates and standardizes addresses.
      • DPV® (Delivery Point Validation): Confirms whether addresses actually exist.
      • NCOALink® (National Change of Address): Identifies people who have moved.

4. How does Pub 28 define the structural hierarchy of a mailing address?
   • • Pub 28 approaches addresses from the bottom up, moving from the least specific to the most specific information. The hierarchy includes:

• • • • Bottom: ZIP Code and ZIP+4.
      • Moving up: City and State.
      • Primary Address Line: House number, pre-directional, street name, suffix, and post-directional.
      • Secondary Information: Unit designators (Apt, Suite, Unit) and unit numbers.

5. What are the key database design implications based on the principles in Pub 28?
   • • There are three core principles for managing address data based on Pub 28:

• • • • • Treat all address elements as strings, not numbers (e.g., to preserve leading zeros in ZIP codes).
        • Understand what constitutes the primary address field or line for parsing and processing.
        • Ensure the database structure supports the USPS’s address hierarchy, even if it doesn’t perfectly match data entry screens.

Learn more here.

FAQs on CASS™ Certification

1. What does CASS™ stand for, and what does it actually certify?
   • • CASS™ stands for Coding Accuracy Support System. It does not certify mailers; it certifies the software that processes addresses. This certification means the USPS has approved the software’s ability to standardize addresses, assign correct ZIP/ZIP+4 and carrier route codes, and validate delivery points.

2. Is CASS™ processing mandatory, and what is its primary business value?
   • • Yes, running mail through CASS™-certified software is mandatory for qualifying for USPS automation and presort discounts. However, its real value goes beyond discounts—it creates structured intelligence by validating addresses, identifying issues, and providing detailed address characteristics to help mailers make informed decisions about which pieces to mail or suppress.

3. What does a DPV® (Delivery Point Validation) result of ‘Y’, ‘D’, and ‘N’ mean in a CASS™ report?

• • • Y: The address is confirmed as a valid delivery point.
    • D: The address is confirmed but is missing secondary information (like an apartment number).
    • N: The address is not confirmed but falls within a known range of addresses.
    • A blank result means the address could not even be evaluated.

4. What do the DPV® footnote codes BB and CC indicate?

• • • Footnote BB: The entire address matched, including secondary information. This is considered a highly confirmed address.
    • Footnote CC: The street address matched, but secondary information was present (like a unit number) that the USPS could not validate because they do not require it for delivery (e.g., at a retirement community with internal mail sorting).

5. Does an address failure in CASS™ mean it is undeliverable?
   • • Not always. The article notes that some addresses fail CASS™ but are still deliverable (e.g., new construction or valid non-standard military addresses) because the carrier has local knowledge. Conversely, some addresses can pass CASS™ but still be undeliverable for the specific recipient if they have moved (which NCOALink® addresses). CASS™ is necessary but not sufficient on its own for achieving high deliverability.

Learn more here.

FAQs on NCOALink®

1. What is NCOALink® and what is its primary goal?
   • • NCOALink® stands for National Change of Address Link. It is a product that matches your mailing list against the USPS database of change-of-address (COA) orders filed by individuals, families, and businesses. Its main goal is to increase your good mail volume by improving deliverability to the right people at their current addresses, in addition to helping you meet regulatory requirements.

2. What regulatory requirement does NCOALink® help mailers meet?
   • • NCOALink® is the primary pre-mailing solution used to meet the Move Update requirement. This requirement is mandatory for First-Class Mail and Marketing Mail seeking USPS automation discounts and means you must verify that the addresses are current within a specific timeframe prior to the actual mailing.

3. What are the three levels of match confidence NCOALink® provides?
   • • NCOALink® looks for three levels of match confidence:

• • • • Business match (B): Indicates a business name matched to a COA.
      • Individual match (I): Indicates a specific person’s full name matched to a COA record at that address.
      • Family match (F): Indicates only the surname and address matched to a Family COA on file.

4. What are some distinct types of address changes identified by NCOALink®?
   • • NCOALink® identifies several types of address changes, including:

• • • • COA (Change of Address): A standard move where the new address is provided.
      • MLNA (Moved, Left No Address): Indicates the person, family, or business moved but did not provide a new address to the USPS.
      • BCNO (PO Box Closed, No Forwarding Order): Applies to PO Box closures without a forwarding address.
      • Temporary moves: For temporary COAs lasting a couple of weeks up to 6 months, though the temporary address is not included in the data.

5. Why is the Move Effective Date (MED) important when evaluating NCOALink® results?
   • • The Move Effective Date (MED), provided as the Month and Year, offers a level of confidence in the data. The most recent COAs have a higher rate of modification, correction, or deletion because people’s plans change or they make mistakes and file a new COA to correct the old one.

Learn more here.

FAQs on ACS™ (Address Change Service) Data

1. What is ACS™ and what is its fundamental purpose in address quality management?
   • • ACS™ stands for Address Change Service. Its fundamental purpose is to provide feedback about undeliverable mail to the mailer. It’s an official USPS product designed to help mailers capture Undeliverable As Addressed (UAA) mail data and use it to close the loop on their customer data lifecycle, impacting future mailings.

2. In which part of the customer data lifecycle is ACS™ data used?
   • • ACS™ data is primarily used after mailing. The article states that after a mailing, you need to “capture Undeliverable As Addressed (UAA) mail data to close the loop and impact future mailings,” which is the function of ACS™.

3. How is ACS™ data used in conjunction with CASS™ results?
   • • ACS™ data provides critical real-world context for addresses that have issues identified by CASS™. For example, if an address has a CASS™ result indicating “missing secondary information” (DPV® D and footnote N1), a mailer should check their prior ACS™ data to see if they’ve successfully delivered there before. If the ACS™ data shows a return with an “Insufficient Address” indicator, then the unit number must be obtained before mailing again.

4. Where is ACS™ mentioned as one of the essential tools for serious mailers?
   • • ACS™ is listed in the Pub 28 content as one of the 13 Address Information System Products and Services offered by the USPS. The article emphasizes that these tools, including ACS™, are “essential components of a complete address quality strategy” and not optional add-ons for serious mailers.

5. What is an example of a specific return code or message a mailer might receive via ACS™?
   • • A mailer might receive an ACS™ return indicating “Insufficient Address”. This is a signal that an address, even one that may have passed some CASS™ validation steps, is missing critical information (like a unit number) necessary for final delivery by the carrier.

Learn more here.

FAQs on Connecting CASS™, NCOALink®, and ACS™

1. Why is CASS™ processing alone not sufficient for achieving high deliverability rates?
   • • CASS™ is necessary but not sufficient because it only tells you if an address is structurally valid (i.e., if the house number, street, and ZIP+4 exist). It does not tell you if the intended recipient still lives there. For that, you need to use NCOALink® to check for a Change of Address. The article notes that an address can pass CASS™ “with flying colors but still aren’t deliverable” to the person you are trying to reach.

2. What is the overall purpose of connecting CASS™, NCOALink®, and ACS™ data?
   • • The combined data from these three tools creates actionable intelligence that drives sophisticated decision-making. It moves beyond simple compliance (which CASS™ satisfies for discounts) to a comprehensive strategy that determines:

• • • • CASS™: If the address exists and is properly formatted.
      • NCOALink®: If the person still lives there.
      • ACS™: What happened to the undeliverable mail pieces.
    • This allows mailers to make smarter decisions about which pieces to mail, which to suppress, and which require additional verification.

3. How do you use the different data sources to make a decision about an address missing secondary information (DPV® D, Footnote N1)?
   • • When a CASS™ report shows an address is confirmed but missing secondary information (DPV® D and footnote N1), the decision requires context from ACS™.

• • • • If previous ACS™ data shows you’ve successfully delivered there, you may choose to mail and rely on the carrier’s local knowledge.
      • If you’ve received an ACS™ return indicating “Insufficient Address,” you should suppress the piece until the unit number is obtained, as the carrier could not complete delivery.

4. How does ACS™ data “close the loop” on address quality?
   • • ACS™ (Address Change Service) is the post-mailing feedback mechanism. It captures data on mail pieces returned as Undeliverable As Addressed (UAA). By analyzing these returns, you get final confirmation on which addresses are truly deficient, allowing you to update your database and improve the process for future mailings.

5. Beyond postal discounts, what are three major business areas impacted by a comprehensive address quality strategy?
   • • The article emphasizes that address quality is a business issue, not just a mailing issue, with implications extending to:

• • • • • Fraud Risk Management: Identifying unusual address patterns or high-risk characteristics (e.g., CMRA, PBSA, or validation failures) can signal potential fraud.
        • Customer Service: Knowing an address has an issue allows the organization to proactively reach out to confirm information, reducing costly customer service calls and improving retention.
        • Regulatory Compliance: Financial and healthcare institutions, in particular, must ensure their addresses meet industry-specific regulations (like the Bank Secrecy Act or HIPAA), which requires the detailed insight provided by CASS™ and NCOALink® codes.

Learn more here.

FAQs on Address Quality Best Practices

1. What is the fundamental, multi-point approach for improving address quality throughout the customer data lifecycle?
   • • Improving address quality requires a comprehensive approach that touches multiple points:

• • • • Data Entry: Implement verification tools to ensure data is correct upon initial entry.
      • Database Maintenance: Conduct regular hygiene and processing.
      • Just-in-Time Processing: Run final checks, like CASS™, immediately before a mailing.
      • Post-Mailing: Capture Undeliverable As Addressed (UAA) mail data via services like ACS™ to close the loop and update your database.

2. What is the most critical best practice for database design, based on USPS addressing standards?
   • • The first principle for database design is to treat all address elements as strings, not numbers. This is essential because converting to an integer will cause you to lose leading zeros (e.g., in ZIP codes) and prevent proper handling of non-integer addresses (e.g., “123 1/2 Main Street”).

3. Why must a business’s definition of a “perfect address” go beyond the USPS standard of Complete, Correct, and Current?
   • • For comprehensive business operations, an address must also be:

• • • • Connected: A good name/address combination for the intended recipient.
      • Credible: Verified from a fraud risk perspective.
      • Compliant: Meets industry-specific regulations (e.g., Bank Secrecy Act requirements for a physical address). What the USPS considers perfect for postage discounts is not always what your business needs for security or compliance.

4. What is the mandatory regulatory requirement for mailers seeking USPS automation discounts, and which process is the primary solution?
   • • Mailers must meet the Move Update requirement, which verifies that addresses are current within a specific timeframe prior to mailing. NCOALink® (National Change of Address Link) is the primary pre-mailing solution used to meet this requirement.

5. What is the primary function of CASS™-certified software, and is it a one-time process?
   • • CASS™ (Coding Accuracy Support System) certified software is mandatory for postage discounts and standardizes and validates the structural accuracy of an address. However, it is not a one-time fix. The data changes constantly, with thousands of delivery points, ZIP+4s, and carrier routes being added or changed monthly, meaning regular, ongoing CASS™ processing is required to stay current.

6. What action should a mailer take when CASS™ returns a DPV® result of ‘D’ and footnote ‘N1’?

• • • Result D: Address is confirmed but missing secondary information.
    • Footnote N1: Secondary address data (like an apartment number) is required but not present.
    • The best practice is to check your prior ACS™ data. If you have an ACS™ return indicating “Insufficient Address” for that record, you should suppress the mail piece and try to obtain the missing unit number before mailing again.

7. How do you distinguish between the three NCOALink® match levels for a move update?
   • • NCOALink® distinguishes matches by confidence level:

• • • • Business match (B): Business name matched to a Change of Address (COA).
      • Individual match (I): Specific person’s full name matched to a COA.
      • Family match (F): Only the surname and address matched to a COA filed as a Family move.

8. Why is it important to pay attention to the Move Effective Date (MED) on an NCOALink® match?
   • • The MED indicates when the person stated they were moving. The most recent COAs (those with a current or prior month MED) have a higher risk of modification, correction, or deletion because people’s plans may change or they may file a correction, making older COAs more reliable and stable.

9. What critical information does ACS™ provide that is missing from CASS™ and NCOALink®?
   • • ACS™ (Address Change Service) provides the actual outcome of a mail piece, giving feedback on why it was Undeliverable As Addressed (UAA). It is the final piece of the puzzle, confirming if a structurally valid address (CASS™-approved) is now outdated or insufficient for the carrier to deliver.

10. What is the overarching cost-benefit of a complete address quality strategy?
    • • While CASS™ provides mandated postage discounts, the strategy’s primary benefit is mitigating the real cost of poor quality, which extends beyond mail-specific expenses. It is an investment that reduces downstream costs, such as:

• • • • Increased customer service calls.
      • Regulatory compliance penalties.
      • Loss of customer satisfaction and retention.
      • Fraud risk.

The key is recognizing that “address quality is a business issue, not just a mailing issue.

Learn more here.

FAQs on The #1 Rule in Address Data Quality: Nothing is 100% (And Why That’s OK)

1. What is the fundamental, “number one rule” in address quality?
   • • The number one rule is that nothing is 100%. According to the article, mailers should never expect to achieve 100% deliverability, and more importantly, they shouldn’t try to, as this goal reveals a fundamental misunderstanding of the process.

2. Why is 100% deliverability impossible to achieve, even with the best tools?
   • • The impossibility of 100% deliverability is due to the human element in the address ecosystem. It involves over 300,000 mail carriers in the United States, each with local knowledge who make daily decisions about recording and handling addresses. This variability is inherent to the process and cannot be fully captured by any database.

3. Does investing in all available tools, such as CASS™, NCOALink®, and ACS™, guarantee 100% deliverability?
   • • No. The article uses the example of a client who had implemented CASS™, NCOALink®, and ACS™ and still had about 1% of mail come back undeliverable. While these tools improve quality significantly, the residual undeliverable mail is part of the reality of address data and the variability introduced by the human element.

4. What is the core issue with a business leader asking, “What are we paying for if we can’t get to 100%?”
   • • The core issue is a fundamental misunderstanding of address quality. Such a question is based on the flawed premise that address quality is a static, one-time fix that can be perfected, rather than an ongoing process that is inherently subject to change and local human interpretation.

5. What is the overall message regarding the 1% of mail that may still come back undeliverable even for best-practice mailers?
   • • The message is that this residual undeliverable mail is simply the reality of address data. It is a natural part of a system that involves constant change and human variability, and the goal should be to maximize good mail volume rather than pursue an impossible 100% deliverability rate.

Learn more here.