The process of correcting and formatting mailing addresses to USPS-approved specifications.
Definition
Address standardization (also called address verification or CASS certification) is the process of cleaning each mailing address against USPS specifications: correcting misspellings, expanding abbreviations, adding ZIP+4 codes, formatting capitalization, and confirming the address actually exists in USPS databases. The process is typically automated through CASS-certified software.
Why it matters
USPS requires standardized addresses for automation discounts (cheaper postage). Standardization also catches typos and incomplete addresses before they become undeliverable mail. A clean, standardized list lowers postage cost, increases deliverability, and produces a more trustworthy customer database.
Example
A chiropractic clinic uploads a CSV of 1,200 patients to a direct mail platform. Standardization corrects 78 addresses (typos, missing apartment numbers, wrong ZIP codes) and rejects 14 as invalid. The cleaned list produces 92 fewer returned postcards over the campaign than the unstandardized version would have.
Related terms
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- House List — A mailing list of your existing or past customers, built and owned by your business.
- PRSRT STD — A USPS Marketing Mail postage class indicia indicating bulk-rate, presorted, non-First-...
- Direct Mail — Promotional or transactional mail sent through the postal service to a targeted list of...
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