# Questions for a mailing-list cleanup provider

Ask what is included and how to read the corrected file.

# Mailing-list cleanup questions

Approximate list size:
Source of the addresses:
Planned mailing date and mail class:

Ask the provider:
- Do you offer NCOALink move updates through a current USPS license?
- Which CASS-certified address-matching software is used?
- Are duplicate checks included, and how do you decide two rows are the same recipient?
- Which input fields do you need?
- Will you return the original address, proposed change, and a plain explanation of each result code?
- Which records will still need our attention?
- How will the file be transferred and deleted?

When the file returns, check apartment and suite numbers, leading zeros in ZIP codes, unexplained missing rows, and contact preferences. Apply accepted corrections to the main contact system so the next mailing uses them too.

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From Scribble: https://scribblecards.com/blog/ncoa-cass-mailing-list-checklist

Editorial review: 2026-09-25

## Sources

- USPS PostalPro: [NCOALink product and licensed providers](https://postalpro.usps.com/node/545), accessed 2026-09-25.
- USPS PostalPro: [CASS certification program](https://postalpro.usps.com/certifications/cass), accessed 2026-09-25.