CASS Certified™ ZIP + 4® Coding. DPV® (Verifies Known USPS Delivery Points).

CASS™ is a certification program used by the United States Postal Service® to ensure the quality of address standardization and ZIP + 4 coding software. To receive postal discounts, your mailing list must be run through CASS Certified software prior to mailing based on the following timeframes:

  • Automation presort discounts require the mailing list be processed within 180 days of your mail date.
  • Carrier route discounts require the mailing list be processed within 90 days of your mail date.
  • Basic presort discounts require the mailing list be processed within one year of your mail date.

Some addresses cannot be standardized and will not receive a +4 code. This happens when the address does not match a valid delivery address to which the Post Office™ delivers mail. These are potentially problem addresses. Error codes are offered to help you understand what might be missing or incorrect with these addresses.

ZIP + 4® coding works in ranges so if an address falls within a street number range, a ZIP + 4 will be assigned. However, at this point there is no guarantee the address is a valid delivery point to which the Postal Service™ delivers mail. To confirm whether or not an address is a known USPS® delivery point, the DPV Product takes address validation to another level. It identifies whether or not an address matches the file of USPS delivery points. Together, ZIP + 4 and DPV processing help you eliminate undeliverable mail and reduce mailing costs.


Input: Output:
Mr. and Mrs. Johnson Mr and Mrs Johnson
123 Apple Boulevard 123 NE Apple Blvd
Anytown, MN 55123 Anytown MN 55123-0012
CRRT = 004
DLVPT = 23
Check Digit = 6
LOT # = 0168
LOT Order = A

The LACSLink product provides new addresses for addresses that have been converted, modified or changed due to USPS® changes or changes required for the 911 emergency system. No move has taken place; this is only an address conversion.

Address conversions typically involve the changing of rural route and highway contract addresses to city style addresses. During this process you will also find renumbering and renaming of existing city style addresses. The LACSLink database is separate from the NCOALink® database and addresses remain on the file indefinitely. LACSLink is considered to be part of the required address standardization process.

To reduce the amount of Undeliverable As Address (UAA) mail, you must use the converted addresses when mailing.


The SuiteLink product provides suite (secondary) information to business addresses, building a more accurate and complete address which in turn increases deliverability. SuiteLink matching is a component of the address standardization process.

Have Questions?

We do the complicated list processing work to make it easy for you. Contact us so we can provide the right custom lists for your business.