USPS Address Validation


June 22, 2023

Have you ever experienced shipment delays or returned items due to address issues? If so, you’re not alone. Delivery failures and undeliverable mail affect countless individuals and businesses each year.

Over six billion mail items are returned annually as Undeliverable As Addressed (UAA), costing the United States Postal Service (USPS) around $2 billion. One of the key factors contributing to these delivery challenges is address validation.

You, other individuals, and businesses can avoid costly shipping delays, dissatisfied customers, and undeliverable mail with a reliable method to verify addresses. That’s where USPS Address Validation becomes an indispensable tool for validating mailing addresses.

In this article, we delve into the world of USPS Address Validation, exploring its process, benefits, drawbacks, and alternatives.

Visit to locate the nearest post office in California, Texas, Florida, Illinois, Michigan, and ensure your address list is correct and deliverable.

Is There a Way to Verify a Mailing Address?

If you’re wondering whether there’s a method to verify a mailing address, look no further than USPS Address Validation. It’s a reliable and efficient tool that ensures addresses are correct and deliverable. 

What Is the USPS Address Validation?

USPS Address Validation is a helpful service offered by the United States Postal Service that allows you and other people, including businesses, to verify the validity and deliverability status of specific addresses.

Validation allows you to check against the comprehensive USPS address database if a provided address exists. 

USPS Address Validation can also help verify if an address meets the necessary USPS formatting guidelines for successful mail delivery, such as capitalized letters and a valid ZIP+4.

USPS Address Validation can offer you peace of mind. Whether you’re sending a personal letter, a package to a loved one, or essential documents, knowing that the address is valid means your mail is highly likely to reach its destination without hiccups.

Suppose you’re running a business, such as e-commerce. In that case, USPS Address Validation ensures your products or services reach customers at the correct deliverable address.

USPS manually tests 3% of business mail to ensure address accuracy before it enters the mail stream. But this process is changing soon, thanks to Seamless Acceptance technology. 

Available to full-service mailers, Seamless Acceptance electronically validates business mail and identifies the sender.

Address verification helps minimize shipping errors, reduce costs from undeliverable packages, and maintain high customer satisfaction, especially considering customer change of address is very common.

Why USPS Address Validation?

Various factors can negatively impact the effectiveness of addresses. For one, people make mistakes. Customers make between 4.7% and 8.4% errors when filling out forms or entering information like a correct address.

Adapting to the 10 to 20 new ZIP (zone improvement plan) codes that USPS introduces annually can take several years for many Americans. The fact that ZIP+4 codes can change monthly due to evolving coverage areas and new construction areas leading to new addresses doesn’t help.

If a database isn’t comprehensive enough, these factors can lead to many incorrect addresses. Using USPS Address Validation to clean up mailing address lists can help ensure that mail and packages arrive at their intended destinations without issues.

Benefits of Accurate Address Validation

Whether you’re just trying to receive and send parcels without frustration or a business attempting to fulfill customer orders, using the USPS Postal Address Verification tool offers several benefits. 

Ensures Greater Operating Efficiency

With accurate addresses, you save time, effort, and resources. For many businesses, it’s more cost-effective to correct addresses at the start than to deal with issues like returns later, which can be around 17% to 30% of the handling and transportation costs.

Streamlining your address data can reduce the chances of failed deliveries, returned mail, and customer complaints, leading to smoother operations and improved efficiency.

Helps to Fight Fraud

Fraud is a common concern, with 2.8 million reports in 2021. This problem is true for many individuals, and more so if you’re operating a business. Validating shipping addresses before you accept orders can help detect suspicious transactions and reduce fraud risk.

Taking a proactive approach, such as using USPS Address Validation, can protect your business from financial loss, chargebacks, and reputational damage and provide customer security.

Increases Marketing ROI

While the digital advertising industry is growing exponentially, there’s still value to traditional ads, like catalogs and mailers, as many people enjoy using their senses of sight and touch. 

You can enhance your marketing efforts in multiple ways through accurate address validation.

For one, correct address information ensures your marketing materials reach the proper recipients, maximizing the effectiveness of your campaigns. It can also reduce returned mail. 

With lower printing, postage, and labor costs, you can increase your return on investment (ROI).

Improves Customer Satisfaction

Timely and accurate deliveries are crucial for customer satisfaction. 

Address validation shows your commitment to a seamless experience. You build customer trust and loyalty by preventing lost or delayed deliveries due to inaccurate addresses.

Lowers Mailing & Shipping Costs

Validating addresses before mailing or shipping eliminates wasteful resources, such as postage fees, printing, and package labor. 

For example, accurate address validation helps avoid expensive Address Correction Penalties, costing around $84 for FedEx packages weighing over 200lbs.

6 Cons of Using the USPS Postal Address Verification Tool

While the USPS Address Validation tool offers numerous advantages, you must know its limitations too. Here are six drawbacks to consider:

Slow User Experience

Validating addresses using the USPS Address Verification Tool can be time-consuming and tedious. You need to enter each part of the address in separate fields and navigate through multiple pages to view the results.

While having a correct address list offers many benefits, particularly to businesses, dealing with many addresses can become increasingly frustrating.

No Address Autocomplete

USPS Address Verification Tools lack an autocomplete feature. In other words, you must enter each complete address manually. If you’re a business, manually entering addresses increases the chances of errors, such as typos or missing components.

Not having an autocomplete feature also means you need to spend time verifying an extensive address database. While third-party autocomplete tools exist to solve this problem, such as Google Address Autocomplete, there may be costs associated with using them.

Missing 15 Million+ US Addresses

The USPS database includes 160 million mailing addresses. Still, it doesn’t cover the 15 million non-postal addresses serviced by private carriers like FedEx, UPS, and DHL. USPS also doesn’t keep a database of residential or business customers.

If you’re a business, relying solely on the USPS database can result in missing valid customer addresses. Thus, you need to explore solutions beyond the USPS APIs (Application Program Interfaces) to validate non-postal addresses, which can eat your bottom line.

No International Data

It makes sense for the United States Postal Services to focus on domestic mail services. However, this also means that USPS’s address verification tools don’t provide services for international addresses.

If you’re an individual or business trying to ship abroad, you may need to search for international address validation tools. Unfortunately, while free options are available, you must pay for comprehensive address databases.

Lacking Useful Metadata

Metadata provides additional information that can improve data quality and enable reuse. While the USPS Address Validator offers some metadata, such as carrier notes and vacancy status, it has limitations, such as time zones and ZIP code types.

Incomplete address information, such as missing metadata points, can delay package processing and delivery and lead to undeliverable mail. An interrupted delivery process can lead to increased costs, reduced operating efficiency, and lower customer satisfaction.

Strict Terms of Service (ToS)

The USPS imposes strict terms and conditions on using its address validation APIs. The USPS Address Validation tool allows individual verifications, not batch processing or database cleansing. Violating these terms can result in the revocation of your access to the database.

For businesses, you won’t be able to verify multiple addresses at once or validate, identify, and correct your address database with USPS’s database. In other words, address verification will cost you time and money.

How to Validate an Address With the USPS Address Lookup Tool

Validating an address using the USPS Address Lookup tool is a straightforward process. Here’s a step-by-step guide:

  1. Access the USPS Address Lookup tool.
  2. Enter the address you want to verify.
  3. Submit the request and wait for the validation results.
  4. Review the output to determine the deliverability and accuracy of an address.

Understanding the USPS Output

When you validate an address using USPS Address Validation, you receive valuable or incomplete information about the address, depending on the search results. 

The USPS Postal Address Verification Tool provides different types of results when validating addresses.

  • Multiple valid matching addresses: When you verify an address, the tool may identify multiple valid matching addresses. In short, several possible addresses closely match the one you’re searching for.
  • Fully enumerated address: The validation tool may provide a complete and accurate address, including all the necessary details and the ZIP+4 code.
  • Partial address match: The address verification service may return a partial match result, meaning that the address you entered is incomplete and is missing the ZIP+4 code.

What Is the Process Behind Validating an Address?

Address validation involves a series of steps to ensure an address is accurate and deliverable. The process involves:

  1. Address parsing: First, the validation process divides the address into different parts, such as the house number, street name, and street type. Parsing helps to organize and identify each component of an address.
  2. Address standardization: Next, the verification process formats the address according to the standards set by USPS. CASS-certified (Coding Accuracy Support System) providers correct spelling errors, fill in missing information, and align the address with USPS formatting standards.
  3. Matching with USPS database: The standardized address is then compared to the USPS address database. The validation procedure flags ones that don’t have identical matches as potentially invalid or requiring further verification.

Delivery Point Validation

When you get the USPS Address Validation output, you can expand it using Delivery Point Validation (DPV) to confirm that a given address corresponds to an actual delivery point.

DPVs are essential indicators to determine that a specific address is accurate and can receive mail. 

DPV indicators include the following:

  • DPV confirmation indicator “Y”: This indicates that the address is valid and can be used for shipping. It assures that the address meets USPS standards.
  • DPV confirmation indicator “D”: This means that the building or house number (primary) is correct, but the suite, apartment, or unit number (secondary) is missing from the user’s entry. While delivery may be possible, “D” addresses require manual review.
  • DPV confirmation indicator “S”: When this indicator appears, it signifies that the primary number of the address is confirmed, and the secondary number is present but has failed DPV confirmation. This suggests that the address may not be deliverable as entered.
  • DPV confirmation indicator “N”: The primary and secondary numbers of the address have failed DPV confirmation, meaning the address is likely invalid or not deliverable.
  • DPV confirmation indicator “-“: When your results don’t lead to a match, the address cannot be submitted for DPV confirmation. This suggests that the address may be invalid or unrecognized in the USPS database.

LACs And LACslink®

Locatable Address Conversion System (LACS) is an important dataset that ensures accurate address information, particularly when converting rural to city-style street addresses during the implementation of the 911 system. 

The primary purpose of LACSLink is to maintain up-to-date and standardized address data. It helps ensure that addresses align with current postal standards, enhancing mail delivery efficiency.

USPS Valid Address

A USPS-valid address is the best output when using the address validation tool, as it refers to an address that’s been successfully verified and confirmed as deliverable. These addresses adhere to USPS formatting standards and are recognized as legitimate mailing destinations.

What Is the Standard Address Formula?

The USPS address standardization follows a formula to ensure uniformity and accuracy. It typically includes the necessary elements for an exact match, including the recipient or company name, house number, street name, city, state, and postal code.

Here’s an example of a standardized USPS address:

JOHN SMITHRecipient Line
1234 MAIN AVE STE 567Delivery Address Line
ADAMS NY 89101-1121Last Line

Reasons for Receiving Invalid Addresses

An address may fail USPS Address Validation due to various reasons. Here are examples:

Imaginary Address

Sometimes, people provide fake addresses to keep their actual addresses private. Other times, an imaginary address is a possible indicator of a fraudulent order. 

If you’re a business, it’s critical to understand that these addresses are made up and don’t exist.

Incorrect Address

An incorrect address occurs when the information you enter is wrong, either by mistake or due to an error during verification. Errors typically involve misspellings or incorrect address formats, like street or house numbers.

Address Not Occupied

If an address is labeled “Address not occupied,” it means there’s nobody at that location to receive mail. An “Address not occupied” may occur if the building is vacant or newly constructed and is yet to be added to USPS’s mailing address database.

Address Not Registered

Addresses yet to be registered may be invalid, which often applies to new buildings, new occupants, or individuals who avoid receiving direct mail. When you use the Address Validation tool, an “Address not registered” in the system will result in an invalid status.

What Is the USPS API?

The USPS API is a collection of tools that allows entry to an extensive database of over 160 million US postal delivery points and helps ensure accurate address information.

The USPS API includes tools such as:

  • Address API: This API validates and standardizes domestic addresses, city names, and ZIP codes.
  • USPS web tools API: This API allows e-commerce websites and shipping companies to access USPS data for shipping rates and package tracking.
  • Address Matching System API (AMS API): Developers use this API to create address-matching software for verifying address accuracy.

What Does the USPS API Do?

The USPS API allows you, businesses, and even software developers to leverage USPS services and obtain real-time address verification, shipping pricing, tracking information, and even automation.

Benefits of Address Verification APIs

Using an address verification API, such as the USPS API, offers several advantages, including improved address accuracy, faster turnaround times, reduced costs from returned mail or lost packages, and increased overall efficiency.

USPS Address Verification or Third-Party Tools?

While USPS Address Verification provides reliable and accurate results, you may also consider third-party tools for address validation. Third-party tools often offer additional features, like international address validation or more extensive metadata.

If you’re an individual who wants to ensure your deliveries get to where you want them or verify whether you’re address is deliverable, the USPS Address Validation tool may be enough.

However, let’s assume you’re a business that handles large delivery volumes. In that case, deciding whether you need additional address verification features depends on your needs and requirements.

How Do I Get Customer and Technical Support?

If you require customer or technical support regarding USPS Address Validation or related services, USPS offers various channels.

You can contact USPS customer and technical support by calling their dedicated helplines, 1-800-275-8777 and 1-800-344-7779. Alternatively, you can visit the USPS website for the appropriate contact information.

You can also go to your local USPS post office to ask for assistance. offers a post office locator tool to find ones in your area.


  1. What counts as address verification?

Address verification typically refers to confirming a given address’s accuracy, deliverability, and standardization. To ensure validity, it compares the provided address against reliable address databases, such as the USPS database.

  1. What can I use for address verification?

You can use the USPS Address Validation tool or third-party address verification tools and APIs to verify addresses.

  1.  Is USPS address validation free?

The USPS address validation API is free and an excellent option for ensuring your addresses’ accuracy, deliverability, and standardization. That said, there are limitations to the USPS validation tool, which is where third-party tools can come in as alternatives.


  1. Management Advisory – Strategies for Reducing Undeliverable as Addressed Mail
  2. USPS Address Validation
  3. Seamless Acceptance
  4. USPS Address Verification
  5. U.S. Zip Codes
  6. Reducing retail supply chain costs of product returns using digital product fitting
  7. New Data Shows FTC Received 2.8 Million Fraud Reports from Consumers in 2021
  8. Examples of Traditional Advertising
  9. Places API Usage and Billing
  10. USPS Get an Address List
  11. Metadata for Data Management: A Tutorial: Why Do I Need It?
  12. USPS Web Tools™ Application Programming Interface User Guide
  13. Guide to How USPS Address Validation Works
  14. LACSLink
  15. Postal Addressing Standards
  16. Address Checker: Verify Postal Addresses using PostGrid Address Verification
  17. USPS APIs
  18. Contact Us
  19. Understanding USPS API and Address Validation Web Service