The LACSLink® and SuiteLink™ databases

CASS™ requires LACSLink and SuiteLink databases to be installed along with ZP4 before postal form 3553 can be generated to declare automation discounts. LACSLink and SuiteLink databases are included on the ZP4 DVD-ROM.


LACS is the Postal Service™ acronym for Locatable Address Conversion System, which supports the conversion of rural-style addresses to street-style addresses. LACSLink is the Postal Service database that allows ZP4 to automatically perform conversions from one address style to another, as described below.

Most of the records in the LACSLink system are for changing rural-style box numbers to street names. For example,

RR 1 BOX 127A is converted to 17255 SCENIC RD

Some LACSLink records handle renumbered Post Office™ boxes. For example,

PO BOX 123 is converted to PO BOX 555123

Some LACSLink records handle changes when streets are renamed and the house or apartment number also changes. For example,

905 LOWER AVE is converted to 1125 FREEDOM DR

The LACSLink database occupies approximately 370 megabytes and is included on the ZP4 DVD-ROM. Once LACSLink data is installed, ZP4 automatically performs LACSLink conversions like those shown above. The conversion of rural box addresses to street addresses by local governments is ongoing. The LACS flag indicates if any ZIP + 4® database record includes addresses that can be converted using LACSLink.

LACSLink lookups may not be performed after the two-month expiration date of the LACSLink database. The product's license prohibits using LACSLink for the manufacture of address lists, and also prohibits the LACSLink database being exported outside the United States. A "violation" will occur if ZP4 detects LACSLink is being used to generate address lists, and subsequent LACSLink output will be suppressed until a restart code is obtained from Semaphore Corporation to clear the violation. Violation monitoring and enforcement is a requirement of the Postal Service. Semaphore Corporation is required to notify the Postal Service of your name and address when you request a LACSLink restart code. If you repeatedly generate LACSLink violations, the Postal Service will prohibit you from continuing to use the LACSLink system.

LACSLink, SuiteLink and DPV® are required to determine the proper CASS ZIP + 4 code for an address.


SuiteLink is a Postal Service™-maintained database of business addressing information, which enables users to add known secondary (suite) information, so ZP4 can automatically correct incomplete business addresses.

       Before processing   After processing
       -----------------   --------------------
           test corp       Test Corp
           10 main         10 N Main St Ste 201
           nipomo          Nipomo CA 93444-1234
The SuiteLink database occupies approximately 500 megabytes, and is included on the ZP4 DVD-ROM. Once SuiteLink data is installed, ZP4 is able to automatically determine the secondary (suite) information for a company address, if the company is listed in the SuiteLink database. As of May 2011, 21 million records are included in the SuiteLink product.

SuiteLink lookups may not be performed after the expiration date of the SuiteLink database. Once a SuiteLink database expires, you must purchase a current ZP4 edition to continue performing SuiteLink lookups. LACSLink, SuiteLink and DPV® are required to determine the proper CASS ZIP + 4 code for an address.

Semaphore Corporation is a non-exclusive licensee of the United States Postal Service®. The prices of Semaphore Corporation products are not established, controlled or approved by the Postal Service. The following trademarks are owned by the United States Postal Service: CASS, DPV, LACSLink, SuiteLink, Post Office, ZIP + 4, Postal Service, and United States Postal Service. [DA#4.07]