USPS-certified address matching software that standardizes addresses and appends ZIP+4, carrier route, and delivery-point data when available.
CASS
Updated 2026-07-24
Coding Accuracy Support System
Addressing & Lists
Definition reviewed 2026-07-24. Plavidian reference, written from the USPS Domestic Mail Manual. Final mail classification, postage, and preparation are confirmed after list processing and production review.
Need this applied to a real job?
Ask Plavidian™ for an answer grounded in the USPS Domestic Mail Manual, or send us the job and we will confirm the preparation before you print.
Related
Data, addresses and postal optimization
The data cluster: Blueprint to address verification to list processing to postal optimization, mapping and district data.
- mailing list analysis and postage planning with Mailing Blueprint
- address verification and list cleanup (CASS, NCOALink, dedupe)
- NCOALink move update processing
- how to prepare a mailing list
- EDDM or a mailing list: how to choose
- the main direct mail formats and how to choose
- direct mail ideas and campaign examples
- mailing lists and audience targeting
- drop shipment planning and destination entry
- nationwide mailing and USPS drop shipping
- carrier route density and saturation mail guide
- addressing and Move Update requirements guide
- data processing, lettershop and logistics services
- cascade priority data merge case study
- municipal unit-level list reconstruction case study
- political mail printing built on voter data