DSF Details

DSF2 Overview

DSF2 Processing entails two steps - both performed as part of processing. The first step is to process your mailing list through CASS™ (USPS certification process for ZIP + 4® matching software). This step will apply ZIP + 4 codes, carrier route codes, and delivery point, standardize addresses, and correct/verify ZIP codes. The second step is to match your address information to the DSF2 database. Name information is not used in DSF2 processing. Those addresses that match the DSF2 database will be returned to you with a pseudo code to sort your files into walk sequence order, a business/ residential delivery point flag, seasonal address delivery information, etc. Addresses that do not match the DSF2 database will be returned with a set of footnotes identifying possible address errors.

Unlike, ZIP + 4 processing which matches addresses in ranges, DSF2 uses individual delivery points to match address information.

For example:

Your Data: ZIP + 4:  DSF2
123 Main St 110 - 133 Main St 110 Main St
    112 Main St
    115 Main St
    116 Main St
    120 Main St
    124 Main St
    133 Main St

In the above example, the house number is incorrect -- but this error is not identified by ZIP + 4 processing.

DSF2 will help provide valuable delivery point information; will help identify and, in some cases, correct address errors that are not detected through ZIP + 4 processing; and provide the information needed to walk sequence your mailing list. To order DSF2 processing for your mailing list, please read on!

Information About the DSF2 Process

Important Notes:

  • With standard DSF2 processing, additional processing will be required on your part to insert standardized and corrected address information from the DSF2 output file into your mailing list (see output layout).
  • Specialized processing is available that can make DSF2 easier for you. Call for more information about special processing options and prices.
  • Output layout changes for input records with more than 200 characters.
  • For clarification of input requirements and output file layout, please call our technical team at (651) 203-8290.

Classification Reform Information

The new Enhanced Carrier Route postal discounts are available for mail files that meet the density requirements and are sorted in either eLOT™ (sorts mail by approximate carrier-casing sequence) or walk sequence. LOT numbers and sort flag are available through ZIP + 4 processing. Walk Sequencing is available through DSF2 processing. This sortation places mailpieces in the same sequence that the mail carrier for that carrier route will deliver the mail. This saves time for the USPS® mail carrier by eliminating the need to sequence mail prior to delivery and the mailer receives a lower postage rate.

The postal presort required to receive these discounts does require additional processing. The Enhanced Carrier Route density requirements are as follows:

  • High Density Enhanced Carrier Route requires 125 mailpieces or more per carrier route; unless there is less than 125 delivery points within that carrier route, then a mailpiece must be sent to each delivery point within the carrier route.
  • Saturation Enhanced Carrier Route requires the mailpieces be address to 90% or more of the active residential addresses or 75% or more of the active possible delivery addresses (whichever is less) on each carrier route.
  • Saturation Enhanced Carrier Route at Delivery Unit Entry. Saturation must meet the requirements listed above and the mailing is delivered to the Bulk Mail Center (BMC), Sectional Center Facility (SCF), or Destination Delivery Unit (DDU) as required.

Who Can Benefit From DSF2?

Saturation Mailers:
Mailers whose mail is highly concentrated can benefit from walk sequencing postal discounts. DSF2 has the ability to place your mailing in the sequence that the actual mail carrier will walk his or her route. This sequence is identified by a pseudo walk sequence number that is returned on the mail file for addresses that match DSF2. The number is referred to as a "pseudo" walk sequence number because the addresses that exist on your mailing list will be numbered consecutively -- walk sequence numbers will not be skipped for those addresses that do not exist on the mail file.

For Example:

Your Data Pseudo Walk Sequence DSF2 Actual Walk Sequence
    122 2nd St 001
123 2nd St 003 123 2nd St 
124 2nd St 001 124 2nd St 002

125 2nd St 005
126 2nd St 002 126 2nd St    003

Mailers with Deliverability Concerns and Problem Addresses:
By reviewing the *Deliverability Codes returned from DSF2, mailers can predict the deliverability of the addresses on their mailing lists. DSF2 contains every delivery point in the U.S. The addresses that match DSF2 should be deliverable addresses. However, DSF2 does not use name information and, therefore, cannot identify who lives at the address on your mail file. Addresses that do not match to the DSF2 file are likely to contain addressing errors. Some of the following methods have been used successfully to review and correct the addresses that do not match to the DSF2 file:

  • Telemarketing Campaigns - Review address information with the customer.
  • Employees in the Field - Mailers that have employees in the field that regularly visit the addresses on your mailing list can review the potentially problem addresses.
  • Flag On Your Database - A flag on your database that indicates all address information should be reviewed when the customer calls or responds to your mailing. Review all address information at that time.
  • First-Class™ Postcard or Endorsed Mailing - A First-Class Postcard or endorsed mailing ("Address Correction Requested") can provide you with the address corrections you need via the Postal Service™. You can expect a significant number of your potentially undeliverable addresses to be returned to you -- be aware of the costs involved to receive those returns. Address corrections can be made to your database and undeliverable records can be flagged.
  • Address Element Correction (AEC) - AEC is a USPS® process that reviews non ZIP + 4 codable addresses that have been processed through CASS Certified™ software. AEC has been able to correct as many as 40% to 60% of the addresses not codable by ZIP + 4; processing (The percentage rates tend to be slightly lower for addresses processed through DSF2 due to the fact that DSF2 will have corrected some of the addresses that could not be corrected by ZIP + 4 processing.)

Mailers With Special Mail List Interests:
DSF2 is able to append delivery point specific information to a mailing list. The following are DSF2 fields that you can have added to your mailing list:

  • Business vs. Residential Indicator
  • Seasonal Address Flag
  • Vacant Address Flag
  • Drop Point Flag and the Number of Addresses Associated with that Drop Point
  • Commercial Mail Receiving Agencies (CMRA) Indicator
  • Identification of "PO Box Delivery Only" Addresses

DSF2 Example:

Mail File: ZIP + 4 File: DSF2 File:
103 Main St 100 - 110 Main St N 100 Main St N
  100 - 110 Main St S 101 Main St N
    101 Main St N Apt 10
    101 Main St N Apt 15
    105 Main St N
    106 Main St N
    108 Main St N
    102 Main St S
    103 Main St S
    104 Main St S

Results from ZIP + 4 Processing:

Tie between two address ranges; address cannot be ZIP + 4 coded. Recommendation is to review for address errors.

Results from DSF2 Processing

Address is returned as 103 Main St S. Delivery Point is identified as a residential address with a mailbox on the curb. The address is neither seasonal nor vacant. The address is not a mail drop site nor a Commercial Mail Receiving Agency (CMRA).

DSF2 Footnotes Returned: The footnotes that are returned are set in both the ZIP + 4 and DSF2 steps of processing.

  • A1: Not matched to the ZIP + 4 File
  • BB: Matched to the DSF2 File
  • E: Corrected Primary Address
  • K1: Multiple match due to missing or incorrect directional(s)

DSF2 Deliverability Code Returned:

  • 3 - Changed, Good Deliverable

What to expect from DSF2 Processing

The information returned is only as reliable as the information provided by the mail carrier. The DSF2 file is updated monthly, so there is an expected lag time for updating the delivery point information and adding new addresses to the database. DSF2 does not use name information, therefore cannot identify the individual that reside at the mailing address. Addresses identified as "Good, Deliverable Addresses" per DSF2 may be undeliverable due to the mailing name associated with the address or lag times that effect the updates to the DSF2 file. Address identified as "Potentially Undeliverable" may still be deliverable because the mail carrier recognizes the individual's name and delivers the mailpiece regardless of incorrect address information or the address has not yet been updated on the DSF2 file.

DSF2 Processing Output Information

Each output record contains three data areas:

  • Original Input Data - Original information as it was received for processing.
  • Standardized Data - Address information in a standardized format. Includes the newly applied ZIP + 4 code; modified address, city, state, ZIP Code™ information; carrier route; and Delivery Point Barcode (DPBC).
  • DSF2 Footnotes, Data and Score. DSF2 Footnotes will indicate records with changes, corrections, and missing data as identified by the ZIP + 4 process and DSF2 matching process. Delivery point data includes a pseudo walk sequence number, seasonal address flag and business/residential distinction. A DSF2 Score of 1 to 7 will be assigned to each record.