When you certify addresses you will often receive a message that some customer addresses could not be certified. Click CASS > Error Report to get a list of those addresses. The errors in address certification are listed below, but they all mean that the address is misspelled, incomplete, or could be interpreted to mean more than one thing. The best way to solve this is to simply go down the list of incorrect addresses. Many can be fixed by a quick edit. If an address looks correct but still shows up on this report, try looking it up online—the post office may have a different address listed from the one the customer gave you.

10	Invalid input address (i.e., contained a dual address)
11	Invalid input 5-digit ZIP Code
12	Invalid input state abbreviation code
13	Invalid input city name
21	No match found using input address.
22	Multiple responses were found and more specific information is required to select a single or default response. Number inside parenthesis is the number of responses found. (May show only a single response if code "T" is also shown. See below.)
C	Invalid City/State/ZIP The ZIP Code in the submitted address could not be found because neither a valid city, state, nor valid 5-digit ZIP Code was present. It is also recommended that the user check the submitted address for accuracy.
D	No ZIP+4 Code Assigned This is a record listed by the United States Postal Service on the national ZIP+4 file as a non-deliverable location. It is recommended that the user verify the accuracy of the submitted address.
E	ZIP Code Assigned with a Multiple Response
F	Address Not Found The address, exactly as submitted, could not be found in the city, state, or ZIP Code provided. It is also recommended that the user check the submitted address for accuracy. For example, the street address line may be abbreviated excessively and may not be fully recognizable.
H	Missing Secondary Number ZIP+4 information indicates this address is a building. The address as submitted does not contain an apartment/suite number. It is recommended that the user check the submitted address and add the missing apartment or suite number to ensure the correct Delivery Point Barcode (DPBC).
I	Insufficient/Incorrect Data More than one ZIP+4 Code was found to satisfy the address as submitted. The submitted address did not contain sufficiently complete or correct data to determine a single ZIP+4 Code. It is recommended that the user check the address for accuracy and completeness. For example, firm name, or institution name, doctor’s name, suite number, apartment number, box number, floor number, etc. may be missing or incorrect. Also pre-directional or post-directional indicators (North = N, South = S, East = E, West = W, etc.) and/or street suffixes (Street = ST, Avenue = AVE, Road = RD, Circle = CIR, etc.) may be missing or incorrect.
R	No Match due to EWS (Early Warning System)
S	Invalid Secondary Number The secondary information (i.e., floor, suite, apartment, or box number) does not match that on the national ZIP+4 file. This secondary information, although present on the input address, was not valid in the range found on the national ZIP+4 file.
T	Multiple Response Due To Magnet Street Syndrome The search resulted in a single response; however, the record matched was flagged as having magnet street syndrome and the input street name components (pre-directional, primary street name, post-directional, and suffix) did not exactly match those of the record. A “magnet street” is one having a primary street name that is also a suffix or a directional word, having either a post-directional or a suffix (i.e., 2200 PARK MEMPHIS TN logically matches to a ZIP+4 record 2200-2258 PARK AVE MEMPHIS TN 38114-6610), but the input address lacks the suffix ‘AVE’ which is present on the ZIP+4 record. The primary street name ‘PARK’ is a suffix word. The record has either a suffix or a post-directional present. Therefore, in accordance with CASS requirements, a ZIP+4 Code must not be returned. The multiple response return code 22 is given since a “no match” would prevent access to the best candidate.
V	Unverifiable City/State The city and state in the submitted address could not be verified as corresponding to the given 5-digit ZIP Code. This comment does not necessarily denote an error; however, it is recommended that the requestor check the city and state in the submitted address for accuracy.