NCOA Codes & What They Mean

Return Codes Shown in BOS:

10-17 May be undeliverable (poor address quality). Books may or may not be delivered to this address.
21-22 Address didn’t match an address range in the zip+4. Books may or may not be delivered to this address.
23-28 Recipient moved without providing a forwarding address to the USPS. 33 Address is non-deliverable. Books will not be delivered to this address.
36-39 New address information is provided and can be used with confidence. You will need to select the "Click to use this address" in order to update the address. Books will be delivered to the new address if you choose to use it.

Additional information on NCOA codes:

• Return Codes 35, 36, 37, 38 & 39. A move or address update is confirmed. Records with one of these codes have been updated with the addressee’s new address.
• Return Codes 23, 26, 27, 28, & 33. These codes are non-reliable for delivery and a new address needs to be provided.
• Return Code 23. A move or address update is confirmed, but the new address could not be supplied. A possible cause for this is that a change of address card was submitted to the USPS, however the new address provided did not match an address the USPS recognizes as deliverable.
• Return Code 26. The PO Box has been closed, and no forwarding address was supplied.
• Return Code 27. A change of address form was submitted, but no forwarding address was provided.
• Return Code 28. Customer has moved out of the country.
• Return Code 33. Address flagged as Non-Deliverable.
• (Addresses with Return Codes 23, 26,27, 28 and 33 should be taken off your list or researched.)
• Return Code 31. These addresses matched to a record and are valid postal addresses. (These addresses can be mailed to with reasonable confidence.)
• Return Code 32. These records are missing a suite or apartment information. They may or may not be deliverable. 
• Return Codes 10-17. These records may not be delivered due to poor address quality. (Addresses with Return Codes 10-17 should be researched to provide a full and complete address if possible.)
• Return Codes 1–4 and 43–46 indicate that a move is suggested, but there there is not enough accurate data to verify the information. The lower the score, the greater the chance that a move has occurred. 
• Return Codes 21 and 22. For these codes the NCOA check comes up with an invalid city, state or zip combination, or simply cannot find the address in its database or is getting too many responses to make a determination. Essentially, these addresses do not conform to postal standards and cannot be compared against the database. Some of them may be pre-911 addresses. They may or may not be deliverable, depending oftentimes on the whim of the local post office. For example: