The LACSLink™ Product is a secure dataset of converted addresses that primarily arise from the implementation of a 911 system, which commonly involves changing rural-style addresses to city-style addresses. The LACSLink™ Product also contains existing city-style addresses that have been renamed or renumbered.

The U.S. Postal Service® will deliver to either the old or new version of the LACSLink™ address for a period of one year. At the end of this period, the “old” version ceases to be a valid address. It disappears from all postal files except the LACSLink™ file. Without LACSLink™ conversion, the old version of the address can no longer be ZIP + 4® coded or carrier route coded and will be considered undeliverable.

The LACSLink™ Product:

1. Reduces undeliverable mail by providing the most current address information for matches made to the LACSLink™ file.
2. Lowers mailer costs by reducing the number of undeliverable and duplicate mail pieces by using the most current address information.
3. Provides the opportunity for faster product/service marketing through accurate mail delivery.

Effective August 1, 2007, CASS Certified™ software is required to use both LACSLink™ and DPV™ products when processing address lists. This new requirement ensures ZIP + 4® codes will be assigned only when the primary number of the address can be validated using the DPV™ Product and whether the input address reflects any applicable municipality address conversions.