CASS Certification: Reduced Costs and Improved Deliveries
by Marilyn Bunderson
Have you ever been lost in the woods? It happens sometimes. You think you know where you’re going, but your GPS isn’t working, and you veer off course somewhere along the way. Pretty soon you’ve missed grandma’s house and you’re face-to-snout with the big bad wolf. That’s what shipping feels like without proper address verification—packages get lost, misdelivered, or never arrive at all.
What is CASS Certification?
CASS (Coding Accuracy Support System) Certification is the USPS program that helps keep your mail on the right path. It’s a standard that your address verification software meets to prove it can correctly clean, format, and verify addresses.
In short, CASS-certified software helps your packages skip the wolves and go straight to Grandma’s doorstep on time, every time.
Why address verification matters in delivery
Address verification means checking to make sure an address exists and is deliverable, catching errors before a label is printed. It helps your packages get routed correctly and arrive at the right doorstep the first time, avoiding costly delays caused by undeliverable or incomplete addresses.
Similarly, address validation focuses on making sure the address is complete and properly formatted. While the terms are often used interchangeably, they’re not quite the same: Address validation does not guarantee that an address is real or deliverable; it just makes sure it looks right.
CASS-certified software handles validation and verification, giving you the best of both worlds. For ecommerce businesses shipping large volumes, it’s a critical tool for improving delivery accuracy and keeping operations running smoothly. Simply put, it helps make sure your parcels don’t get lost in the woods—or thrown to the wolves.
How the CASS Certification process works
The two-stage CASS™ Testing Process
CASS Certification requires a two-part testing process designed to ensure address validation software meets USPS standards.
Stage 1 is an optional test with answers that acts like a practice run. It allows software providers to identify and correct any issues in address formatting, coding, or delivery point validation before taking the real test.
Stage 2 is the required certification test without answers. This formal test is administered by USPS and must be passed to receive official CASS Certification. It confirms that the software can accurately process and standardize addresses in line with USPS expectations.
How much does it cost to get CASS certified? USPS does not charge a direct fee to take the CASS Certification test. However, businesses developing or licensing CASS-certified solutions may incur internal costs for development, testing, and compliance efforts.
Certification Requirements
To achieve certification, software must support key USPS tools that verify and enhance address accuracy. Delivery Point Validation (DPV®) confirms whether a given address actually exists and can receive mail. LACSLink® (Locatable Address Conversion System) helps convert outdated or non-standard addresses such as rural route numbers or renamed streets into the correct, USPS-recognized format. These tools are essential for ensuring that addresses are both accurate and current.
Certification Cycles and Renewal
CASS Certification follows a recurring update cycle to ensure ongoing accuracy and alignment with USPS standards. The current cycle is known as Cycle O, which sets the benchmark for all certified software. To maintain certification, software providers must retest and renew according to USPS requirements. This ensures that address validation tools remain up to date with any changes in address data, postal formats, or delivery rules.
What CASS Certified software can do
CASS-certified software is like a GPS for your shipments, keeping addresses clean and on track so they don’t end up somewhere they don’t belong. More than simply formatting an address correctly, it enhances accuracy and reliability. That means fewer delays, fewer returns, and a smoother customer experience.
How it helps:
Address standardization and cleaning It converts addresses into the standardized USPS format, removing extra characters and fixing spacing issues to ensure consistency across your records.
Address correction and updating It flags incomplete or incorrect addresses and updates them using USPS-approved data, helping you avoid misdeliveries due to typos, missing ZIP Codes, or outdated street names.
Address verification and validation It confirms that an address actually exists and can receive mail, cross-checking with the USPS database to ensure deliverability before a label is ever printed.
Qualifying for USPS postage discounts By ensuring compliance with USPS standards, CASS-certified software enables you to qualify for bulk mailing discounts. It cuts costs while improving delivery performance.
Whether you ship hundreds or hundreds of thousands of packages, CASS-certified software keeps your operations efficient and your deliveries dependable.
Benefits of using CASS Certified solutions
CASS Certification doesn’t just help you stay on the path, it paves the road. With fewer wrong turns and smoother deliveries, using a certified solution has several benefits.
Improved mail deliverability CASS-certified software ensures that mail is delivered accurately and efficiently by validating addresses before anything is sent out. With fewer errors and more accurate delivery points, packages and mail are more likely to reach their intended destination on the first try with no detours, delays, dead ends, or getting lost in the woods.
Reduced undeliverable and returned mail Returned or undeliverable mail isn’t just frustrating, it’s expensive. By catching invalid or incomplete addresses early, CASS-certified solutions dramatically reduce the number of packages sent to nowhere. That means fewer reroutes, fewer manual fixes, and fewer headaches for your shipping team.
Postal discounts for bulk mailings CASS Certification is a requirement for many USPS bulk mailing discounts. If you’re sending out mail at scale, CASS-certified address validation helps you qualify for lower postage rates, and that saves you significant money on large campaigns or high-volume shipping operations.
Enhanced customer experience Customers expect their packages to arrive quickly and reliably. CASS-certified software helps you deliver on that promise, minimizing missed deliveries and reducing the need for customer service follow-ups. The result? Happier customers, fewer complaints, and stronger brand loyalty.
Data quality management improvements Clean address data isn’t just good for shipping; it’s good for business. CASS-certified tools help standardize and maintain accurate address records across your systems, reducing manual errors and improving the quality of your customer data over time.
Cost reduction and efficiency Every failed delivery comes with a cost: time, postage, materials, and customer trust. CASS-certified solutions help you avoid those unnecessary expenses by streamlining address processing and eliminating inefficiencies at the source. Better data leads to better outcomes and lower costs.
Optimize your address accuracy
Without verified addresses, your packages risk straying off course—just like Little Red Riding Hood taking the long way to Grandma’s house. CASS-certified solutions keep your deliveries on the straight path, improving accuracy, reducing costly returns, and qualifying you for USPS discounts along the way. Don’t let your parcels get lost in the woods.
Learn about EasyPost's Address Verification API today and reduce delivery errors with seamless address validation.