There are over 152 million delivery locations in the United States requiring a combined effort from the USPS and the postal industry supply chain to ensure an efficient and cost effective delivery. The term Presort Reference Data defines the set of files used by software to communicate the various USPS Drop Ship locations and mailpiece groupings required for this work-sharing. The accuracy and timeliness of this data is critically important to the effectiveness of USPS mail delivery process.

There are five sets of presort reference data that include over 30 files. These files define how, where, and when USPS mail can be sorted to receive the desired work-share discount. The presort reference data includes:

· Labeling Lists - a set of files that define the current 3- and 5-digit ZIP Code schemes needed to correctly sort and label mail into bundles, trays, and containers.
· Drop Ship Product - defines the default drop sites (DDU, SCF, ADC, NDC, and FSS) and any redirections that the USPS may have imposed. (A redirect helps the USPS optimize its network by redirecting mail from one destination to another)
· Zone Chart Matrix - helps identify the zone of a mailpiece. The zone is based on the distance from the facility the mailpiece entered the mail stream, to where the mailpiece will eventually be delivered
· Delivery Statistics File - defines the number of Post Office boxes and business/residential deliveries on city, rural, and highway contract routes for every ZIP Code in the United States.
· City State Product - a comprehensive list of ZIP Codes with corresponding city and county names.

So how does your software use the presort reference data to ensure mail is processed efficiently and at the lowest combined cost? The steps below show one example of how software uses this data to prepare letters in a walk sequence order, at the standard mail rate, and dropped at a Sectional Center Facility (SCF).

Step 1 - Presort instructions - The software receives a list of addresses, let's assume these have already been passed through an address quality process (CASS, Merge/Purge, Suppression, NCOALink, and DSF2 walk sequence). A set of instructions from the user defines how the list of address records should be sorted. These instructions include piece level detail and sort level information including weight, thickness, mail class, piece type, destination drops, mailing date, etc.

Step 2 - Validation phase - The software makes sure the presort reference data is valid at the time of mail induction using the mailing date assigned in step 1. A warning or error is issued by the software if the data will be out of date.

Step 3 - Sort phase - The address list is passed through a sort routine that utilizes the Domestic Mail Manual (DMM) to determine which presort reference data files are used for sorting. In this example, the software uses the City State Product file to help assign address pieces to carrier route trays and 5-digit carrier route trays. The L002 Labeling List file is used to assign residual pieces to 3-Digit carrier route trays. The software then determines if there are enough pieces in these trays to qualify for the SCF discount. It also looks at the Drop Ship product file to determine if these containers can be dropped at the SCF. The Mail Direction file (part of the Drop Ship product file) is then used to identify any redirects that the USPS has listed for each destination. It is then determined if any of the redirections apply to any pallets that were created. Finally, the ZIP Code and Carrier Route information is validated against the Delivery Statistics File for each record in the list. This is used to determine the level of saturation that can be claimed (Saturation, High Density, or High Density Plus).

Step 4 - Report phase - The Delivery Statistics File is used to calculate the total delivery points, active delivery points, and total residential for the ZIP Code/Carrier Route combination. This information is included on the USPS Qualification Report. The software creates a Mail.dat file and a postage statement using the calculations created during the sort phase. If this had been a Periodicals, Bound Printed Matter, or Priority Mail sort, the Zone Chart Matrix file would have been used to determine postage rate.

Step 5 - Printing labels and preparing the mail - The mail can now be printed in sort order and placed in trays and pallets for delivery to the SCF. The software reviews the City State Product file and Labeling List file to generate the destination line (destination city, state and ZIP) on the tray labels, facing slips, and container labels. Some software allows you to schedule an appointment using the critical entry times and drop ship hours for the SCF stored in the Drop Ship Product file.

The postal industry is an ecosystem of supply chain partnerships that require presort reference data to effectively deliver the mail. The accuracy and timeliness of this data is critical to allow the USPS to lower costs and drive efficiencies through work-sharing.