ZP4 Errors and Warnings

ZP4 can detect over forty different kinds of errors when checking an address. A single address can easily have multiple errors.

Error numbers 1.x through 7.x are serious enough to prevent ZP4 from finding a ZIP + 4® code for an address. Error numbers 8.x through 14.x are only warnings because they are not serious enough to prevent ZP4 from finding a ZIP + 4 code.

Error 1.1: State not found. The input record state is not a valid two-character abbreviation. Try providing a ZIP Code™ instead.

Error 2.1: City not found. The input record city is not in ZP4's list of cities for the input record state. Try providing a ZIP Code instead of a city.

Error 3.1: Street not found. The input record street is not in ZP4's list of streets for the input record city. Usually caused by misspelled street names that ZP4 can't guess how to correctly spell. Sometimes streets are listed in an unexpected way. If a street does not receive mail delivery, it might not be included in the database.

Error 4.1: Address not found. The input record does not have a house number that can be found in ZP4's list of addresses for the input record street. This error can also apply to invalid box numbers at Post Office™ box and rural route addresses.

Error 5.1: Uncomputable +4 range. ZP4 can't compute the ZIP + 4 code for the address because of non-numeric characters in the input record house number or in the Low, High, ZIP + 4, or Hi+4 fields of the database as shown in the list of addresses on a street. ZP4 will provide the correct five-digit ZIP Code.

Error 5.2: +4 unavailable. A complete ZIP + 4 code is not available, because the database thinks this address is still an undeveloped lot. ZP4 will provide the correct five-digit ZIP Code.

Error 6.1: Multiple streets match. The input record is ambiguous, because more than one street name in the database matches the input address, and there is not enough information to let ZP4 choose from between the multiple choices. For example, if the database lists both 100 EAST MAIN ST and 100 WEST MAIN ST, then the input 100 MAIN ST might be considered a multiple match. Some multiple matches can be avoided by using the DPV® database for verifying specific addresses.

Error 6.2: Multiple addresses match. The ZIP + 4 database is ambiguous, because more than one ZIP + 4 database record matches the input address. For example, if a street has an address record for houses numbered from 100 to 500, and another record for houses numbered from 300 to 600, then the address 400 is a multiple match to both records.

Error 7.1: Time ran out. There wasn't enough time to process the request. Trying again or simplifying the address may avoid this problem.

Warning 8.1: Company phonetic match used. ZP4 was able to match the input address to an address in the ZIP + 4 database that included a company name, but the input company name and the database company name only matched phonetically, not exactly.

Warning 8.2: First company match used. There are multiple records in the ZIP + 4 database at one address that match the company and address in the input record. ZP4 used the first of the multiple records to determine the ZIP + 4 code.

Warning 9.1: State determined from city. The input record state is not a valid two character abbreviation, but ZP4 could determine a valid state from the input record's city name.

Warning 9.2: State determined from ZIP®. The input record state is not a valid two character abbreviation, but ZP4 could determine a valid state from the input record's ZIP Code.

Warning 10.1: City phonetic match used. The input record city is not correct, but was matched to a phonetically equivalent city name by ZP4.

Warning 10.2: City determined from ZIP. The input record city is not correct, but ZP4 could determine a valid city from the input record's ZIP Code.

Warning 10.3: Acceptable city name used. The Postal Service™ does not consider the input record city designation acceptable for addressing purposes. ZP4 has standardized the city to an allowable name.

Warning 11.1: Street phonetic match used. The input record street is not correct, but was matched to a phonetically equivalent street name by ZP4.

Warning 11.2: Predirection dropped. A street name like N MAIN ST was standardized to MAIN ST.

Warning 11.3: Predirection added. A street name like MAIN ST was standardized to N MAIN ST.

Warning 11.4: Suffix dropped. A street name like BROADWAY AVE was standardized to BROADWAY.

Warning 11.5: Suffix added. A street name like MAIN was standardized to MAIN ST.

Warning 11.6: Postdirection dropped. A street name like MAIN ST N was standardized to MAIN ST.

Warning 11.7: Postdirection added. A street name like MAIN ST was standardized to MAIN ST N.

Warning 11.8: Predirection standardized. A street name like NORTH MAIN ST was standardized to N MAIN ST.

Warning 11.9: Street standardized. Non-directional, non-suffix words in a street name were standardized. For example: THIRD ST to 3RD ST, BOX to PO BOX, RURAL RT to RR, 3 AVE to 3RD AVE. This warning also occurs when an alternate street name replaces a less preferred name, or if an empty address field is changed to "General Delivery".

Warning 11.10: Suffix standardized. A street name like MAIN STREET was standardized to MAIN ST.

Warning 11.11: Postdirection standardized. A street name like MAIN ST NORTH was standardized to MAIN ST N.

Warning 11.12: Street missing. The input record's address field was empty.

Warning 12.1: Unit standardized. An address like 5 MAIN ST SUITE A was standardized to 5 MAIN ST STE A.

Warning 12.2: Unit missing. The ZIP + 4 database indicates the address should have a unit like an apartment or suite, but none was specified in the input record.

Warning 12.3: Unit not found. A unit such as an apartment or suite was specified in the input record, but none was found in the ZIP + 4 database.

Warning 12.4: Unit unverified. A unit such as an apartment or suite was specified in the input record, and the ZIP + 4 database indicates units exist at the address, but there is insufficient detail in the database to verify the input unit is valid. This warning can be avoided by using the DPV database for verifying specific units.

Warning 12.5: Rural box not found. The input record includes a rural route box number not found in the ZIP + 4 database.

Warning 13.1: Leftovers found. The input record address contained words ZP4 could not guess how to use.

Warning 14.1: ZIP not found. ZP4 tried to determine the correct city or state name from the input record ZIP Code, but the ZIP is not in the database's list of valid ZIP codes.

Warning 14.2: ZIP changed. The input record has a ZIP Code, but the correct five-digit ZIP Code for the address is different.

Warning 14.3: +4 changed. The input record has a +4 code, but the correct +4 code for the address is different.


  • Go to the ZP4 home page.