Fix
PreferredCorrect the line. Re-check. A good address is the default path for First-Class and for Certified.
Address verification that reduces returned mail
CASS and NCOA are included on every piece. Addresses are standardized and change-of-address runs before print. Fewer returns. Not a USPS delivery-time promise.
CASS vs NCOA
Two USPS programs. Two jobs. They run on the production path.
| Program | What it does | What it is not |
|---|---|---|
| CASS | Checks the address against USPS files so the piece can be mailed. | Not change-of-address. Not a list you download and keep. |
| NCOA | Checks USPS move files for a new address of record. | Not a rewrite of the document you uploaded. Not every move. |
| Tracing | Scan status on qualifying First-Class letters and postcards. | Not address cleanup. Not legal proof. How tracing works → |
| Certified Mail | Proof the piece was delivered. | Not CASS. Not NCOA. Certified Mail → |
CASS and NCOA are USPS programs for domestic addresses. Do not assume them on international pieces.
What CASS does on a job
CASS is the USPS Coding Accuracy Support System. It is how a street, city, state, and ZIP become a mail-ready address. The check runs after you have addresses on the job.
A scanned letter, a CSV row, and a hand-typed line all go through the same check. CASS does not invent a recipient. It does not guess a missing apartment if USPS cannot match the line. When the address does not match, the piece is flagged for you.
Scan addresses from the file, import a CSV, or add them by hand. You choose how duplicate names and addresses are handled. What’s in the product →
What NCOA does on a job
NCOA is National Change of Address. People and businesses file moves with USPS. The production path checks those files before print so fewer pieces leave for a street the recipient has left.
Not every move is in the file. A recipient who never filed, filed late, or moved without USPS notice can still generate a return. We do not publish a match rate. We do not promise zero returns.
We do not rewrite the PDF, Word file, or image you uploaded. The document stays yours. Change-of-address processing is on the mail piece, not inside your billing system. Statements & invoices →
Where verification sits on a job
After addresses. After proof. Then a human confirms.
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Addresses in
From the document, a list, or by hand.
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Proof
AI proposes setup. CASS and NCOA run on the production path.
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Quality
Flagged pieces show in address quality. You review them.
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You approve
Nothing prints until a human confirms.
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We produce
Print, postage, deliver to USPS on your mail date.
Flagged addresses
A flag is a review, not an auto-send.
Still mail
First-Class onlyOn First-Class you can still mail a flagged piece. Delivery is not guaranteed. Tracing still needs a good address.
Certified
No still-mailOn Certified Mail a flagged address must be fixed or taken off the job. You cannot mail it anyway.
What this is not
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Not tracing
Scan status is a different job. Tracing vs tracking →
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Not Certified proof
Proof of mailing is a mail option you add. Certified Mail →
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Not a list-cleaning product
Verification runs on the job you send. We do not sell a standalone NCOA file.
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Not document rewrite
You own the file. We do not edit statement or notice copy inside your system.
Address verification FAQ
Does USMail.ai verify addresses?
Yes. CASS and NCOA are included on every piece. You review flagged pieces, then you approve. It is not a guarantee that every piece will deliver.
What is CASS?
CASS is the USPS Coding Accuracy Support System. It checks the address against USPS files and standardizes it so the piece can be mailed. Street, city, state, and ZIP become a mail-ready address. CASS is not change-of-address, not tracing, and not Certified proof.
What is NCOA?
NCOA is National Change of Address. It checks USPS move files before we print. Not every move is in the file. We do not rewrite the document you uploaded.
Does address verification speed up USPS delivery?
No. Verification reduces undeliverable mail. It does not change USPS transit time. USMail.ai does not publish delivery-day promises.
Can I mail a flagged address on Certified Mail?
No. On Certified Mail a flagged address must be fixed or taken off the job. You cannot mail it anyway. On First-Class you can still mail a flagged piece. Delivery is not guaranteed. Certified Mail →
Is address verification the same as tracing or Certified Mail?
No. CASS and NCOA clean and update the address on the production path. Tracing is scan status on qualifying First-Class letters and postcards. Certified Mail is proof of delivery. They are three different jobs. Tracing → · Certified →
Get started
Open the app. Addresses are checked on the job you send.