USPS Address Quality
USPS Address Quality: CASS and NCOA
Accurate addresses are essential for timely delivery and USPS compliance. USPS provides two options to ensure address quality: CASS™ Certification and NCOA® (National Change of Address) processing. These services can be used separately, or in tandem, to maximize deliverability.
What is CASS?
CASSâ„¢ (Coding Accuracy Support System) is a USPS certification process that standardizes and validates addresses.
- Included service: All addresses are run through CASS if NCOA is not selected.
- Purpose: Ensures addresses are complete, correctly formatted, and valid for USPS delivery.
- Checks performed:
- Validates city, state, ZIP, and street combinations.
- Assigns proper ZIP+4â„¢ codes.
- Runs Delivery Point Validation (DPV®) to confirm the address exists for USPS delivery.
Benefits of CASS:
- Improves address consistency and accuracy.
- Reduces undeliverable mail.
- Ensures addresses meet USPS formatting standards.
What is NCOA?
NCOA® (National Change of Address) is a USPS-licensed database containing 48 months of permanent change-of-address (COA) records.
- Requirements:
- Requires at least 100 unique addresses in a mailing to qualify.
- If the mailing does not meet this minimum, CASS will be run by default.
- Purpose: Matches customer addresses against USPS COA records and updates them if a recipient has filed a move order.
Benefits of NCOA:
- Provides the most up-to-date USPS move data.
- Helps meet USPS Move Update requirements.
- Reduces mail delays and undeliverable pieces.
- Often used in tandem with CASS for maximum accuracy.
DPV: Delivery Point Validation
DPV® is a USPS process that confirms an address exists as a deliverable point (house, apartment, PO Box, etc.).
- Pass: The address is valid and USPS can deliver mail to it.
- Fail: The address is incomplete, inaccurate, or not recognized as deliverable.
Impact: Failing DPV means the mailpiece may be returned or undeliverable.
Certified Mail Note: If you have a Certified mailing, USPS requires addresses to pass DPV in order for labels to be produced.
- Passing DPV Codes: Y (validated), S (valid, missing secondary).
- Failing DPV Codes: N (not validated), D (secondary invalid).
How They Work Together
- NCOA + CASS:
- NCOA first updates addresses with USPS change-of-address data.
- CASS then standardizes and validates the updated address, applying DPV.
- CASS Only:
- If NCOA is not selected or the job does not meet the 100-address minimum, addresses are run through CASS.
Return Codes Quick Reference
When addresses are processed through CASS or NCOA, return codes indicate whether the address passed validation or why it failed. Below is a simplified guide:
Code | Meaning | Impact |
|---|---|---|
DPV = Y | Delivery Point Validated | Address is deliverable. (Certified labels can be produced.) |
DPV = S | Valid but Secondary Missing | Deliverable, though may require unit/apartment correction. (Certified labels can be produced.) |
DPV = N | Not Validated | Address not recognized as deliverable; must be corrected. |
DPV = D | Secondary Present but Invalid | Address has a unit number, but USPS does not recognize it as valid. |
NCOA: Moved/Forwarding | Address updated with a USPS move record | Address replaced with forwarding address, if available. |
NCOA: Moved, No Forward | Recipient filed a move, but no forwarding address on record | Mail will be undeliverable. |
NCOA: No Match | No COA record found | Original address remains; CASS will still validate for accuracy. |
CASS: Invalid City/ZIP | City, state, or ZIP do not match USPS data | Must be corrected before mailing. |
CASS: Nonexistent Address | Street/number combination is not recognized | Address is undeliverable. |
CASS_NCOA Return Codes
📌 For the full technical list of return codes, see the USPS PostalPro DPV Guide.