USPS Address Standardization API

Quickly check, correct, format, and standardize addresses in real-time to ensure successful deliveries to your customers.

Robust Address Standardization Features

When you combine our USPS address standardization api with these excellent features, anything is possible!

Our USPS address standardization tool delivers everything you need, plus more to efficiently deliver mail directly to recipients without issues and seamlessly build powerful address standardization applications.

 DPV Return Code System

Confirm the existence of a specific address.

 LACSLink Processing

Update old rural route addresses.

 POSTNET™ Delivery Point Barcodes

Qualify for additional USPS discounts.


Correct and update business records.

 Intelligent Mail Barcodes™

Qualify for additional USPS discounts.

 Census Data

Includes CMSA, FIPS, and more. Also includes Census block and Census track number.

 Legislative Data

Includes congressional district number and more. Also includes state legislative upper and lower.

Address Standardization

Automatically update addresses to adhere to the United States Postal Service’s (USPS) standards. This ensures successful deliveries.

Address Correction

Automatically correct shipping addresses before packages are sent to recipients to save money & stop undeliverable mail.

Address Validation

Compare each customer address with the USPS database & find a match. If a match is found, then that address is deliverable.

Residential Delivery Indicator

USPS RDI, or Residential Delivery Indicator, identifies whether a U.S. address is classified as residential or business.

Proper Case Formatting

Get data in Proper Case format rather than the default uppercase format for automatic scanning of bar codes.

Carrier Route

Carrier route codes can be presorted to the carrier route level to take advantage of presorting postage discounts.


Ensure correct primary & secondary data to give mailers the ability to sort their mailings in approximate carrier-casing sequence.

Geolocation Data

U.S. addresses can yield latitude & longitude, area code, time zone, & daylight savings information as an optional return.

Legislative Data

Return legislative information, including the congressional district number along with the senate & house district of the address.

Why Choose Esendex’s Address Standardization API

Esendex’s postal address standardization API is fast and reliable. We have fully redundant server farms that deliver results in a fraction of a second. A trustworthy address standardization tool is crucial if you collect Canadian and US postal address data through a sales or enrollment portal.

Address standardization APIs can be used to help you save time, money, and resources by standardizing addresses for deliverability before mail and packages are sent out. PAV API helps businesses ensure data quality for all U.S. customers. Choose us because we have been experts in bulk address standardization since 1999. We are a company you can trust.

Volume-Based Pricing

With per-transaction pricing and customized plans, our address API fits every budget.

Customer Satisfaction

We strive to provide the best customer service, which is why we offer an SLA.

Great Coverage

Our address API standardizes addresses across the U.S., U.S. territories, & even Canada.

Emergency Support

After-hours emergency? No problem! We offer 24/7 emergency support.

1. World Class Support

Most address standardization services don’t have active online support channels customers can speak to when they need it the most, and we understand.

That’s why we have 24/7, around the clock emergency support for our address verification tool. You can expect fast response times, fast troubleshooting, and email, chat, and phone support.

2. US Postal Address Standardization

Our USPS address standardization API enables you to leverage your business in the United States and Canada without any interruptions. Don’t worry about the distance! Get USPS standardized addresses in both countries.

3. Government Level Security

Our API for address standardization USPS is 256 Bit Encrypted (typically only reserved for governments and militaries), SOC2 Type 2 Certified, HITRUST Certified.

Hardware-based standardization servers are strategically located throughout the US-owned and operated by Esendex.

How Address Standardization APIs Works

The USPS address standardization api works by allowing developers to submit addresses to be standardized programmatically. This can be helpful for companies or organizations that have a large number of addresses that need to be standardized.

Overall, address standardization helps to ensure that mail is delivered correctly and efficiently. It also helps prevent undeliverable mail, saving time and money.

ROI, Cost, & Data Management

Address standardization can help companies with ROI, Cost, & Data Management in a few ways. First, companies can more easily track and manage their data by having a standardized address format.

This can lead to better decision-making and more efficient use of resources. Additionally, address standardization can help reduce costs associated with mailing and shipping. Finally, companies can improve their customer service and communication by standardizing address data.

Programmable Address Standardization

Our USPS address standardization API integrates with your website, database, or system using SOAP (Simple Object Access Protocol) or REST (Representational State Transfer) protocols.

Unlimited Address Standardization Plan

We offer an affordable, unlimited USPS address standardization plan that won’t limit you by usage and transactions while at the same time saving your business money.

What Does Our Address Standardization API Do?

We help you save time, money, and resources by verifying addresses for deliverability before mail and packages are sent out. PAV helps businesses ensure data quality for all U.S. customers.

Keep in Mind…

Address standardization greatly increases delivery time and the likelihood of a successful delivery. However, standardization alone does not guarantee deliverability or validity, which is why our PAV API also includes address correction and address verification.

  • Corrects spelling errors
  • Formats with USPS capitalization
  • Fixes incorrect abbreviations
  • Formats ZIP Codes to ZIP+4
  • Identifies missing information

Examples of Address Standardization

Based on the examples below, you can see our address standardization API can fix incorrect abbreviations as well as format zip code to zip +4 and so much more.

Fixes Incorrect Abbreviations

Formats to ZIP+4

USPS Address Standardization Pricing

Pick the plan that works best for you.

No hidden fees and no long-term commitment required. Best in industry pricing with either our unlimited or per transaction pricing.

We will not be undersold*. With Esendex you get the most accurate and advanced Postal Address Standardization API at the absolute best pricing anywhere.

All Plans Include
  • Residential Delivery Indicator
  • Code Documentation
  • HTTPS Protocol
  • Geolocation
  • Instant Address Verification
  • CASS Certification

Simple USPS Address Standardization Documentation

We know that implementing an address standardization API into your business takes time. That’s why we made our documentation easy to understand and implement into all of your projects!

You’ll have no problem connecting with the address standardization tool using any programming language capable of REST or SOAP calls, as it was created by developers who wanted nothing more than making sure you could get up and running quickly without having trouble understanding what is happening or how things work underneath the hood.

Build Your Apps Faster

  • Uncomplicated API References
  • Code in Multiple Programming Languages
  • Technical Customer Support
  • Helpful FAQ Section for Dev

The Esendex Difference

Since the early 2000s, Esendex has been one of the industry’s most trusted address standardization providers. The truth is we do things differently.

Our vision is to shape your connections to the world through reliable, usable, and adaptable Communication and Data APIs.

24/7 Support – Lowest Pricing – Multiple Service Channels

What Our Customers Have to Say

Michael K.

President, Program Development, 1-10 employees
Used the API for: 30+ years

“We have used PAV API for over 30 years. Since switching to Esendex we have noticed increased accuracy at a fraction of the cost of other available services. I haven’t found anything we don’t like about PAV API.”

We’ve been rated 5 out 5 stars on Capterra and GetApp.

Benefits of Using an Address Standardization API

Address verification APIs are useful for every company, from local corner stores to global corporations. No matter how large or small, all companies benefit from being able to reach the correct customers to saving time and money and more.

  • Accuracy – Increase accuracy in campaigns and customer contact.
  • Speed – Return bulk address standardization results in seconds.
  • Data Management – Ensure customer information is up-to-date.
  • Coverage – Connect across all U.S. territories and Canada.
  • ROI – Improve campaign results, customer satisfaction, and ROI.
  • Savings – Reduce costs from undeliverable mail and returns.

USPS address Standardization can be used in so many ways to verify your customers address effectively. Here are a few ideas you could implement into your business to decrease undeliverable mail, save money, and cleanse your database.

eCommerce Platforms

Establish your online store ensuring products get delivered to customers.

3rd Party Logistics Companies

Ensure shipments from warehouses arrive on time to their correct destinations.

Background Checks

Verify personal information to run credit and save money by verifying backgrounds.

Parsing Address Data

Cleanse and verify raw incoming address data from anywhere by parsing it.

Get your United States Postal Service address standardization API questions answered here.

1. What is address standardization?

Address standardization is making sure that an address is correctly formatted according to the standards set by the country’s postal service. In the United States, the postal service is the United States Postal Service (USPS), and they have a specific format that they require for addresses.

2. What is CASS address standardization?

CASS address standardization is making sure an address meets USPS standards. This includes verifying the address exists, checking for errors, and making sure it is properly formatted. CASS-certified APIs are used to perform this process, ensuring that addresses are standardized correctly.

3. What error codes does the USPS address standardization web tool return?

The United States Postal Service (USPS) address standardization web tool can return several different types of error codes. These include invalid zip code, no match found, multiple matches found, address not found, city not found, state not found, country not found, missing or invalid.

4. What is a standardized USPS address standardization?

A standardized address is an address that has been verified and confirmed to meet the requirements of the United States Postal Service (USPS). An address can be standardized using the USPS Address Standardization API, which is a service that can be used by businesses and individuals to verify and correct address information.

5. How do you standardize address data?

The most common and accurate way is to use the Esendex’s address standardization process. This process can be done through our USPS address standardization API. To use our USPS address standardization API, you will need to provide an address that you would like to standardize. The address will then be run through the USPS address database and will be corrected to the most accurate address that is on file.

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Let’s start sending, together.