Locatable Address Conversion System (LACS) corrects address lists electronically for areas that have undergone permanent address conversions.  The LACS database consists of address conversions that the USPS has obtained and verified, primarily as a result of Emergency 911 system implementation.  These permanent address conversions typically involve renumbering rural route, highway route, and box numbers as city-style addresses.  After this conversion, mail addressed to the "old style" address will only be delivered for 3 years.  Input address information you provide is standardized according to USPS requirements and then matched against the LACS file. If a match is made, we provide you with the permanent address conversion.

LACS benefits include the following:

• Reduces undeliverable mail by providing the most current address information for matches made to the LACS file
• Prevents the need for duplicate mail pieces or re-mailing after address corrections are received since the address correction is applied prior to mailing
• Lowers mailer costs by reducing the number of undeliverable and/or duplicate mail pieces by using the most current address information
• Provides the opportunity for faster product/service marketing through accurate mail delivery

You receive the following from LACS processing:

• The original input address from the mailer
• The input address, standardized and appended with the Zip+4 code, if possible
• A standardized new address when the standardized input address matches the old address on the LACS file
• PS Form 3553, Automation Discount Qualification (CASS Report)
• National Deliverability Index (NDI) report - breakdown of deliverable address information

When no address matches are found, you receive:

• The original input address
• The standardized Zip+4 coded version of the input address
• PS Form 3553 (CASS Report)
• NDI report