What is the USPS DPV® confirmation indicator, and how to use it

USPS DPV confirmation indicators are part of USPS's CASS Certification program and show USPS employees (and anyone else who knows where to look) whether an address was deemed deliverable or not. For example, a “Y” response in the DPV Match Code (dpv_match_code in your documentation) field indicates that the address is USPS deliverable (even if secondary indicators like unit number, apartment number, etc., exist, this address is complete and includes those numbers).

Many other statuses can populate and indicate address labels, and we'll discuss those below and how to interpret them. You can also watch this quick video if you're one of our visual/audio learners.

Smarty empowers your business with products that give you access to the USPS DPV confirmation indicator to determine deliverability before shipping bills and products or even sending out a technician to an address. You can try some of them below for free, or continue reading to learn more about delivery point validation.

To fully understand USPS DPV confirmation indicators, we'll need to cover these things:

• What is USPS Delivery Point Validation (DPV)?
• Importance of address validation in mail delivery
• How DPV works: The process explained
• Key components of DPV
• The role of the DPV confirmation indicator
• Benefits of using DPV
• Common DPV footnotes (DPV error codes) & their meanings
• How to interpret the DPV footnotes
• Comparing DPV versus alternative address validation solutions
• DPV in comparison to other technologies
• DPV vs. ZIP+4 Code validation
• DPV vs. geocoding
• DPV vs. Google Maps
• DPV vs. international address validation
• Compliance with USPS standards
• Future of address validation and DPV
• Conclusion and key takeaways

What is USPS Delivery Point Validation (DPV)?

We touched on this above, but Delivery Point Validation (DPV) is essentially a signal that the USPS provides to alert other USPS officials (and people who know how to understand the signal) whether or not the USPS deems an address “deliverable” (meaning that somebody can deliver mail there) down to an actual delivery point. (A delivery point is the final destination for a letter or package carried by the postal service. It's the handoff point between the mail carrier and the intended recipient).

The DPV is mandatory for automation mail discounts and distribution through the USPS.

Additionally, DPV addresses have been standardized, formatted, and corrected to fit the USPS standards and guidelines. Standardized addresses play a significant role in address verification best practices by ensuring that all address components—including street, primary number, secondary unit, and ZIP+4—are validated against USPS records, formatted consistently, and deduplicated in your systems.

Importance of address validation in mail delivery

Address validation (aka address verification) is highly important for successful mail delivery. Checking that an address matches against an authoritative database (like USPS's dataset) is one way to help avoid the pains of sending mail to unverified addresses. (Feel free to read about how to validate an address here.)

For example, when you send mail to addresses that have not gone through the address validation process, your organization is at risk of:

• Wasting time: This is especially true in terms of answering phones from angry customers, tracking down delayed or lost shipments, repackaging and sending out additional materials and products, and the mental load from all of that, which slows down production and weakens company morale. Big problems with a simple fix—validating addresses before mailing.
• Wasting money: Repackaging materials, entirely new materials (if product or supplies are lost or damaged in longer-than-normal transit or you're shipping pharmaceuticals), overtime compensation or additional labor cost to fix problems, and reshipment costs all accrue when you don't validate the address before sending mail — especially when mailing to hard-to-serve areas like a rural route, where delivery precision is critical.
• Damaged reputation: A customer who can't rely on your product to arrive when you say it will, likely won't be a customer, but a damaged relationship that may spread their 1-star review of your company to all of their friends, followers on Instagram, and anyone considering purchasing through you or using your services in the future. Branding is everything, and validating your addresses before sending mail, parcels, or notices can help you protect that name you've built.
• Business decisions based on faulty data: An inaccurate representation of addresses in your database can lead your organization to make faulty decisions regarding scaling measures, marketing metrics, and expansion opportunities. Better business analytics are unlocked with standardized and validated address data.

So, how does DPV play into address validation? When an address is validated as real and mailable, the USPS then attaches a DPV indicator or code to help them streamline delivery on their end and enable you to combine DPV compliance with CASS certification for the option to track your mail with Intelligent Mail barcodes (IMBs).

How DPV works: The process explained

The DPV indicator creation process is simple and precise, and it looks like this:

1. Address is standardized & checked: The submitted address is cleaned and formatted to USPS standards (including ZIP+4) and compared against the USPS DPV database, which includes all known deliverable points.
2. DPV confirmation indicator USPS values are assigned: The USPS will assign a DPV code of “Y,” “D,” “S,” “N,” or “-,” to indicate the level of validity tied to the entered address. We'll discuss what each of these mean in the section, “The role of the DPV confirmation indicator,” below.
3. Address enterer can make smarter business decisions and seek mailing discounts: Knowing whether or not the USPS deems an address as deliverable before mailing can be a huge leg up in your business strategy and operations. Depending on the returned DPV values, your organization may also qualify for discounts on bulk mailing.

Key components of DPV

There are 5 key components to USPS Delivery Point Validation

1. Primary address validation—This is the foundation. The DPV system checks that the house/building number and street name combination exists in USPS records.
2. Secondary address validation—If the primary address is valid but has an apartment, suite, or unit number (or other secondary address indicators), DPV validates that the specific secondary unit exists at that building. DPV is particularly valuable here because most bad data happens at this level, where a user doesn't enter important information or enters blatantly wrong apartment numbers.
3. Delivery Point Confirmation Indicator—USPS returns a code that tells you the validation result. More on that in just a moment…
4. DPV metadata—Along with the main indicator, the USPS provides other metadata for more nuanced information to indicate, for example:
   • Whether the address was vacant (dpv_vacant)
   • If it's temporarily undeliverable according to the USPS (dpv_no_stat)
   • If it's a commercial mail-receiving agency (CMRA) (dpv_cmra)
5. ZIP+4 Code & Delivery Point barcode—When a delivery point is confirmed, DPV ensures the ZIP+4 Code and 11-digit Delivery Point Barcode (DPBC) are correct. This enables automation and helps qualify mailers for postal discounts.

The role of the DPV confirmation indicator

Ah. Here's the section we promised we'd get to. What even is a DPV confirmation indicator?

The DPV confirmation indicator is often referred to around here as the heart of the DPV. It explains the level of confidence the USPS has about their deliverability rating assignment for the address. You can decode each DPV confirmation indicator like this:

Y (Yes): This is fully confirmed. Both the primary (street + building number) and secondary (apartment/unit) match USPS delivery records, and the address is considered real and deliverable by USPS.

D (Missing secondary): Primary is valid, but a secondary (apartment/suite) is expected and missing. Think of a large apartment building where the user didn't input a unit number.

S (Invalid secondary): Primary is valid, but the provided secondary doesn't exist (think, someone fat-fingered the wrong apartment/suite number).

N (No): Neither the primary nor the secondary address datapoints match USPS records. This address is NOT deliverable.

Benefits of using DPV

There are implications for understanding this indicator that lead to better business decisions and making some sweet money, too. Generally speaking, using Delivery Point Validation can help with cost savings on undeliverable mail, reducing customer dissatisfaction, and minimizing faulty manual address correction. Industry-wise, there are even more benefits to using DPV for your organization:

• Ecommerce and shipping: You don't want your customers' packages to bounce back because Unit 42G doesn't exist. Catching invalid or missing secondary addresses during checkout reduces returned packages, wasted postage, and angry customer service calls.
• Marketing and direct mail: You qualify for discounts when your addresses are DPV-verified, standardized, and CASS-certified. Cleaning mailing lists to ensure campaigns reach real doors (and also doesn't go to the same door more than once) saves money by avoiding mail sent to undeliverable points and qualifies you for USPS automation discounts.
• Insurance, financial services, and healthcare: Your policies, loan documents, and explanation of benefits need to go to the right customer the first time. Validating applicant addresses down to the apartment level before issuing policies or statements reduces compliance risk and ensures regulatory correspondence is delivered for the most excellent customer experience.
• Utilities and telecom: When activating a service, knowing whether a delivery point exists at that specific unit is critical for your business. Confirming that “Suite 300” exists at a commercial building before dispatching technicians or sending bills helps you to avoid wasted technician trips and billing errors.
• Fraud prevention: Mismatches between a claimed address and a valid delivery point could signal a fraudulent application for your teams to investigate. Flagging suspicious accounts using the DPV confirmation indicator when the provided unit doesn't exist or is missing reduces the risk of fraud or identity theft.

Common DPV footnotes (DPV error codes) & their meanings

DPV error codes (also called DPV footnotes) provide more granular details and data about why an address match may have failed or how it may need to be adjusted in order to obtain a database match. These footnotes are essentially looked up from USPS's internal hash table of delivery points, ensuring quick and accurate responses for each query.

We've also compiled some common combinations of footnotes that you may run across are listed below with DPV footnote interpretations for you to look at:

• AABB - ZIP Code, state, city, street name, and primary number all match with USPS records. Think of this as the gold standard for an address. You will typically see this response for single-family homes with no secondary information needed (apartment, suite, etc.).
• AABBCC - ZIP Code, state, city, street name, and primary number match, but secondary doesn't. However, a secondary address (one that includes secondary components like a unit number) isn't required for delivery. This is most commonly seen with addresses where a user included “Apt 1” at a single-family house, where it's unnecessary information in order to complete delivery. It's also commonly seen with office buildings or storefronts where mail is delivered without needing suite information.
• AAC1 - ZIP Code, state, city, street name, and primary number match, but secondary does not. In this instance, a secondary indicator (like apartment number) is required for delivery. This response is typically found with addresses linked to multi-family apartments or large office buildings, where a mailpiece cannot be delivered to the correct person without that identification through secondary indicators.
• AAM1 - ZIP Code, state, city, and street name match, but the primary number is missing. In this case, the user forgot or left out the premise number. You will usually see this DPV footnote combo from user errors, where the number field was left blank.
• AAM3 - ZIP Code, state, city, and street name match, but the primary number is invalid. This DPV result can be interpreted as “the street exists, but the building number doesn't exist on that street.” Maybe the user fat-fingered a 5 when they really meant 4, or worse, maybe a bad actor is trying to guess a number that does not exist on that street in order to pull one over on someone.
• AAN1 - When you see an N1 combined with an AA, that means that the ZIP Code, state, city, street name, and primary number match, but there's secondary information, such as apartment or suite, that would be helpful. While this address is considered valid, the USPS has made a note that a unit number would make delivery more precise. This is commonly seen with large multi-unit buildings where some mail still gets delivered without a unit (like to a mailroom or front office), but the USPS recommends specifying it.
• AABBR1 - ZIP Code, state, city, street name, and primary number match. Address confirmed without private mailbox (PMB) info. The address is still valid, but the USPS notes the absence of a private mailbox identifier. You'll see this DPV result if the address is a commercial mailbox service (like UPS Stores), and the customer didn't include their box number. This is particularly important in rural route areas, where a PMB ensures mail reaches the correct recipient inside the CMRA.

A special note on PMBs and commercial mailbox services: The CMRA (Commercial Mail Receiving Agency) table is USPS's internal list of private mailbox providers, like UPS Stores or Mail Boxes Etc., that accept mail on behalf of customers. When USPS validates an address, it checks this table to determine if a PMB (Private Mailbox) number is required for delivery.

If the CMRA table flags an address as a mailbox service but no PMB is provided, USPS may mark the address as incomplete or undeliverable.

How to interpret the DPV footnotes

So what does all of this mean for you and your organization/business? Great question. Ultimately, the decision on whether or not to send mail to an address is entirely up to you, your business, and your compliance measures set by government or local authorities. However, we will share what is commonly interpreted from these DPV footnotes as a general practice.

Comparing DPV versus alternative address validation solutions

DPV confirmation indicators are included in Smarty's US Address Verification, but many other address verification providers don't include that with their metadata and opt for other datapoints instead. We think the more you know, the better decisions you can make.

DPV in comparison to other technologies

There are several address validation and verification technologies out there, and each one is optimized for different goals. If we pit USPS DPV against the most common alternatives, you'll see where USPS pulls ahead of the competition and where other solutions might be a better fit for your organizational success. Feel free to peruse the charts we've included below.

DPV vs. ZIP+4 Code validation

DPV is essentially ZIP+4 plus confirmation of the exact delivery point's existence.

DPV vs. geocoding

Geocoding says “the building exists at this coordinate” — but doesn't know if USPS delivers there. DPV knows USPS can deliver, but doesn't give a map location. Best when used together.

DPV vs. Google Maps

Google is a navigation & convenience tool, not a postal authority. Google will happily guess or overmatch; DPV is strict and authoritative. Google does assist with routing, so long as the address input is standardized and already validated elsewhere.

DPV vs. international address validation

International validation often stops at the building or street level due to a lack of granular data in many countries. DPV is more detailed — but only in the US

Compliance with USPS standards

Because USPS has high standards for mail accuracy and deliverability, running your address dataset through a US address verification tool (like Smarty) will ensure that your list meets those standards.

Not only are you building trust in mail communications, but using and analyzing DPV confirmation indicators will give you sweet additional ROI and ensure your organization receives compliance-related perks, such as:

• Qualifying your mail for USPS automation discounts
• Reducing undeliverable-as-addressed (UAA) mail
• Confidence that you're meeting legal and regulatory compliance requirements
• Consumer protection laws: Regulated communications (e.g., statements, notices, healthcare info) are much more likely to make it to the right spot by validating an address prior to mailing.
• Fraud prevention and risk reductions: Financial institutions, insurance agencies and brokerages, and ecommerce and retail platforms can more easily detect and prevent fraud using DPV. Fraudsters using fake or non-existent apartments won't be issued credit, allowed to open accounts, or ship goods.
• Recordkeeping and auditability: Demonstrating that you sent correspondence to a valid address is possible for industries required to prove correspondence with valid addresses as DPV provides concrete, auditable evidence.
• Contractual SLAs: Many service-level agreements stipulate certain delivery success rates or penalties for non-compliance, and using DPV helps you meet these service standards reliably.

Future of address validation and DPV

Everyone wants to know what the future holds, and for address validation and DPV, we think we can anticipate some pretty cool trends on the horizon, maybe in the next couple of years.

Data is constantly evolving and becoming increasingly granular, dynamic, and usable. Although DPV today is somewhat binary: The address either matches an authoritative dataset or it doesn't, Smarty expects that the future will hold more nuanced metadata features.

Maybe we will get real-time occupancy/vacancy statuses, seasonal or temporary deliverability indicators, last-mile carrier notes (like a gate code or delivery preferences, etc.) Heck, we may even see global DPV-like standards in the near future.

If you geek out about addresses, too, you know what we mean when we say it's fun to speculate.

Conclusion and key takeaways

Understanding and using the USPS DPV confirmation indicator is critical for any business that depends on accurate mail delivery, reduced undeliverable-as-addressed (UAA) rates, and compliance with USPS standards. By validating all the address components, including primary, secondary, and ZIP+4, against USPS's authoritative dataset and interpreting the DPV codes and footnotes correctly, you can save money, improve customer satisfaction, and qualify for bulk mail discounts.

Whether you're mailing to a city block, a rural route, or a commercial mailbox (CMRA), leveraging DPV ensures you're delivering to real, mailable addresses. Behind the scenes, USPS's internal systems make this process fast and reliable, especially when paired with Smarty solutions like US Address Verification and US Rooftop Geocoding.

If you're ready to strengthen your data quality and protect your bottom line, start validating addresses with DPV today. And if you need help navigating the details, Smarty offers powerful tools and APIs to make address validation easy and effective.