MPA

Built by Mail Processing Associates, a print and mail production team that handles list cleanup, CASS and NCOA processing, printing, and USPS mailing under one roof. This page is a free, browser-based tool for mailing address verification and list cleaning, so you can find duplicates and bad addresses before you spend money on print and postage.

What this free mailing address verification scan checks

The scanner reads your CSV or Excel file in your browser and runs a structural review of every record. It is a fast first pass at list cleaning and bulk address verification, the same problems our production team looks for before a job goes to press.

Duplicate detection

Finds exact duplicate rows, repeated addresses, repeated name and address pairs, and multiple people at one household. Every duplicate is a piece you pay to print and mail twice.

Missing field check

Flags records missing a recipient name or company, a street address, a city, a state, or a ZIP code. Incomplete records often cannot be delivered and are not eligible for automation postage.

ZIP and state verification

Checks that each ZIP is a valid 5-digit or ZIP+4 format and each state is a real abbreviation, then cross-references ZIP against state to catch mismatches that signal a typo or a mislabeled record.

Stale-list risk

Uses how recently the list was mailed and cleaned to estimate how many records may now be undeliverable because people moved. Older, never-cleaned lists carry the most decay.

Wasted postage estimate

Combines duplicate rate, bad-ZIP rate, and stale-list risk into a wasted-pieces and wasted-budget range at the cost per piece you enter, so you can see the cost of mailing the list as is.

PO box and column detection

Counts PO box records and auto-detects your column layout, even when headers are capitalized or named differently, so the scan works on real-world exports without manual mapping.

What official cleanup adds

The free scan checks list structure. It does not confirm that an address is real or that the person still lives there. That is what certified cleanup does, and it is the step that actually protects your postage budget before a production mailing.

Why bad list data wastes postage

In direct mail, you pay for every record on the list. Print cost and postage are charged whether or not the piece ever reaches a real mailbox. That makes the mailing list itself one of the largest hidden costs in a campaign, and a dirty list quietly inflates it.

The U.S. Postal Service estimates that roughly 14 percent of Americans move every year. A list that has not been cleaned in a year can therefore have a meaningful share of addresses that no longer reach the intended person. Add in duplicate records, missing apartment numbers, and simple typos, and an uncleaned list can waste a noticeable slice of a print and postage budget on mail that is returned or thrown away.

Certified cleanup reverses most of that. NCOA processing typically matches a high share of recent movers, and a CASS-standardized, deduplicated list delivers far more reliably than a raw export. Running address verification before you print is almost always cheaper than paying full freight to mail records that were never deliverable.

CASS and NCOA in plain English

CASS stands for Coding Accuracy Support System. It is the USPS standard for validating and standardizing addresses. CASS processing fixes formatting, confirms the address is a real mailable delivery point, and adds the full ZIP+4. Think of it as making sure the address, exactly as written, is correct and complete.

NCOA stands for National Change of Address. It compares your list against USPS move records and updates addresses for people and businesses that have relocated. Where CASS fixes the address on the page, NCOA follows the person who moved to their new address.

Most direct mail benefits from both. CASS makes the list eligible for the best automation postage and confirms deliverability. NCOA keeps you from mailing to addresses people have already left. This free scan does neither, it is only a structural preview, but it tells you quickly whether your list is in good enough shape to be worth a full cleanup before printing and mailing.

Clean this list and quote the mailing

When you are ready to move from a free preview to a production-ready list, MPA can run certified address cleanup, deduplicate, presort, and quote the full print and mail in one pass. Explore data services and mailing list services, see how it fits into direct mail, or call (863) 687-6945 to talk to our team. Do not have a list yet? Build a targeted mailing list. Want to model the return first? Try the direct mail ROI calculator.

Frequently Asked Questions

No. This free scan is a preliminary list-structure check. It looks for duplicates, missing fields, malformed ZIP codes, invalid state values, and ZIP and state mismatches using reference data in your browser. It is not official USPS CASS or NCOA processing and it does not validate that an address is deliverable. For production mail, MPA can run certified address cleanup, including CASS standardization and NCOA move updates, before printing and mailing.
No. The free scan runs entirely in your web browser. Your file is parsed and analyzed locally on your own device. It is not uploaded to MPA, and no third-party service sees your data during the free scan. Only if you choose to request official cleanup or a mailing quote can you securely send your file to MPA in a later step, and only after you confirm it does not contain regulated data.
CASS, the Coding Accuracy Support System, standardizes and validates each address against the USPS database. It corrects formatting, adds the full ZIP+4, and confirms the address is a real, mailable delivery point. NCOA, the National Change of Address service, compares your list against USPS move records from roughly the last 48 months and updates addresses for people and businesses that have moved. CASS fixes the address as written. NCOA follows the mover to a new address. Most direct mail benefits from both before printing and mailing.
You pay to print and mail every record on the list, whether or not the piece is deliverable. Duplicate records mean you print and mail the same household two or more times. Undeliverable addresses, missing apartment numbers, and people who have moved produce returned or discarded mail that still cost full postage. The U.S. Postal Service estimates roughly 14 percent of Americans move each year, so an uncleaned list decays quickly. Bulk address verification and deduplication before the mailing remove that waste.
The tool accepts CSV files and Excel files in .xlsx or .xls format. It automatically detects common column names such as name, company, address, city, state, and ZIP, even if the headers are capitalized or labeled differently. It can scan lists up to tens of thousands of records directly in your browser without uploading the file.