Computerized Delivery Sequence

The Computerized Delivery Sequence (CDS) File is a 5-digit ZIP Code™ based electronic customer product that provides and updates delivery sequence address information by carrier route for qualified mailers. Mailers must initially qualify for CDS information through Address Sequence Service, described in DMM 507.7.

The CDS product is distributed to qualified customers on a bi-monthly schedule beginning in February. A weekly update option is also now available.

To obtain additional information about CDS, contact the National Customer Support Center at 800-238-3150. The CDS User Guide is available online at www.ribbs.usps.gov/files/cds. Information on qualifying for CDS electronically can be found at www.ribbs.usps.gov/files/eas.