Direct-mail glossary

CASS certification

Coding Accuracy Support System

CASS is a USPS program that certifies address-matching software to standardize, correct, and validate postal addresses against the USPS delivery file — converting informal addresses into the exact format the postal system can route.

Why it matters

When you upload a customer list to a mail house or direct-mail platform, that list almost certainly contains address inconsistencies: abbreviated street types, missing directionals, wrong ZIP codes, outdated unit numbers. CASS-certified software corrects these to the USPS standard format (e.g., converting "123 main st" to "123 MAIN ST NW") and appends or validates the ZIP+4 code, which tells the USPS exactly which side of which block a piece belongs on. For a small-business mailer, CASS processing means fewer pieces wasted on undeliverable addresses and, in many cases, eligibility for presorted postage discounts that require a certified address file. Without CASS processing, you're mailing blind — a meaningful percentage of your pieces may never reach a door.

CardCadence

How CardCadence handles it

CardCadence does not CASS-certify your uploaded list. Addresses are format-checked on import, and anything USPS won't accept comes back as an address issue in your dashboard — you choose up front whether CardCadence auto-corrects and retries it or skips it. If your list is old or came out of a practice management system, running it through a CASS service before you import will cut down on wasted cards.

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