What is CASS certified address verification?

CASS (Coding Accuracy Support System) is a USPS program that certifies address-matching software. CASS-certified verification, like Pelcro's, parses an address, standardizes it to USPS Publication 28, confirms it is deliverable with DPV, and appends the codes USPS needs for presort.

Why do mailers need CASS certified software?

To earn USPS automation postage discounts, mailers must process their address list with CASS-certified software and keep it current. Using certified software is what lets your mail qualify for the lower automation rates.

What is the difference between CASS and DPV?

CASS is the USPS certification program for the matching software; DPV (Delivery Point Validation) is a check that confirms a specific address is a real, deliverable point. CASS-certified software uses DPV as part of the process.

Does CASS certification include NCOA or change of address?

No. NCOA move updates are a separate USPS process. Pelcro's CASS-certified verification standardizes and validates addresses and appends USPS codes, but it does not perform NCOA move updates.

Does Pelcro standardize addresses to USPS Publication 28?

Yes. Every address is parsed and reformatted to USPS Publication 28, with consistent abbreviations, suffixes and directionals, so your file is consistent before it ships.

Can I verify addresses in real time and in bulk?

Yes. Validate addresses at the point of entry on your sign-up form through the API, or cleanse and enrich an existing list server-side.

USPS address verification · CASS

CASS certified address verification

Validate and standardize every US address to USPS Publication 28 standards, confirm it is deliverable with DPV, and append the codes that qualify your mail for automation discounts.

Trusted by leading publishers worldwide

Already trusted by leading publishers worldwide

Case study

How CASS verification works

See an address pass CASS

Pick an address. Pelcro parses it, standardizes it to USPS format, validates deliverability and appends the USPS codes.

1ParseThe raw address is broken into primary number, street, unit, city, state and ZIP.
2StandardizeEach part is reformatted to USPS Publication 28: abbreviations, suffixes and directionals.
3ValidateDPV confirms the address is a real, deliverable USPS point, or flags it.
4AppendZIP+4, Delivery Point, Carrier Route and eLOT codes are added for presort.

Standardized · USPS Pub 28

123 E MAIN ST APT 4

SPRINGFIELD IL 62701-2234

Parsed
Standardized
DPV checked
Codes appended

DPV: Deliverable · Carrier route C012

Illustrative. Pelcro is CASS-certified; results depend on your data. Pelcro does not perform NCOA move updates.

Who it's for

Mailers who must use CASS-certified software to keep USPS discounts
Circulation teams standardizing addresses to USPS Publication 28
Finance teams protecting automation postage rates

Features

What it does

CASS-certified matching: Pelcro's address matching is certified by the USPS CASS program, which mailers must use to earn automation discounts.
USPS Publication 28 standardization: Addresses are reformatted to the USPS standard: consistent abbreviations, suffixes and directionals.
Delivery Point Validation (DPV): Each address is confirmed as a real, deliverable point, or flagged as undeliverable before you mail.
ZIP+4 and Carrier Route append: ZIP+4, Delivery Point, Carrier Route and eLOT codes are appended to qualify mail for presort.
Real time or in bulk: Validate at the point of entry on your sign-up form, or cleanse an existing list server-side.
Stay CASS-clean: Re-validate your list regularly so it stays CASS-clean, which USPS requires to keep automation discounts.

Last updated November 8, 2026

FAQ

Frequently asked questions

What is CASS certified address verification?: CASS (Coding Accuracy Support System) is a USPS program that certifies address-matching software. CASS-certified verification, like Pelcro's, parses an address, standardizes it to USPS Publication 28, confirms it is deliverable with DPV, and appends the codes USPS needs for presort.
Why do mailers need CASS certified software?: To earn USPS automation postage discounts, mailers must process their address list with CASS-certified software and keep it current. Using certified software is what lets your mail qualify for the lower automation rates.
What is the difference between CASS and DPV?: CASS is the USPS certification program for the matching software; DPV (Delivery Point Validation) is a check that confirms a specific address is a real, deliverable point. CASS-certified software uses DPV as part of the process.
Does CASS certification include NCOA or change of address?: No. NCOA move updates are a separate USPS process. Pelcro's CASS-certified verification standardizes and validates addresses and appends USPS codes, but it does not perform NCOA move updates.
Does Pelcro standardize addresses to USPS Publication 28?: Yes. Every address is parsed and reformatted to USPS Publication 28, with consistent abbreviations, suffixes and directionals, so your file is consistent before it ships.
Can I verify addresses in real time and in bulk?: Yes. Validate addresses at the point of entry on your sign-up form through the API, or cleanse and enrich an existing list server-side. See the address verification API

Get started

Keep your mail file CASS-clean

Validate and standardize every address to USPS standards, and keep your automation discounts.

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