DSF is an approved method outlined in the Domestic Mail Manual for sequencing mail pieces in walk-sequence when not using a simplified address.

Please note: Links to many of the documents on this page are temporarily on the bottom left of this page. They will be returned to their normal place soon.

Who is DSF2® for?

To become a DSF2® Licensed Service Provider, applicant must be in the business of, or planning to be in the business of, providing address verification and list processing services.

First Class Mail

First Class Mail



Standard Mail

Standard Mail


What is DSF?

The DSF Product identifies whether a ZIP + 4® coded address is currently represented in the USPS® delivery file as a known address record. The DSF Product contains vacant, residential, business or seasonal address information. It also identifies if an address is delivered to a curb-side mailbox or by a door-slot. This information will allow for more targeted mailings. DSF processing is one of the approved methods outlined in the Domestic Mail Manual for sequencing mail pieces in walk-sequence when not using a simplified address.

What documentation do I need for DSF?

Once you have decided to apply to become a DSF, the next step is to complete the certification process. The process includes the completion of the following documentation:

  • Application
  • Confidentiality Statement
  • Self-Certification Survey
  • Key Personnel Listing
  • Security Documentation
  • Technical Proposal
  • Licensee Survey
  • Equipment Information

Upon completion of these documents, the license must be executed, including the payment of the appropriate licensing fees.

The annual license fee for DSF2 is $114,000.00.

Featured Resources

Applications/ Forms
Licensing and Certification Key Personnel Form for DSF2®

This document contains an application form, Licensing and Certification Key Personnel Form, for Delivery Sequence File Second Generation (DSF2®).

Applications/ Forms
DSF2® Licensee Agreement

This document provides a license agreement for DSF2®.

Contact Lists
DSF2® Licensees

This document contains a list of DSF2® licensed providers with contact information.

Tech Guides
Advertising Technical Guide

Advertising technical guide for licensed products.

Tech Guides
DSF2® Interface Developers Guide

This document provides a technical guide for DSF2® interface developers.

Tech Guides
DSF2® Flat File Interface Developers Guide

This document contains a technical guide for DSF2® flat file interface developers.

Fact Sheets
Information on Public Seed Records

This document provides facts and additional information on Public Seed records.

Fact Sheets
DSF2® Definition of Throwback Table

This document contains a throwback table for DSF2®.

Quick Service Guides
DSF2® Certification Package

The following material describes the necessary steps of the certification process to qualify for a license to the DSF2 Licensed Service.

Quick Service Guides
How to know if a Record is not a Business

This document provides a quick service guide to know if a record is not a business.

User Guides
DSF2® Licensee Performance Requirements

To achieve DSF2 certification, the Licensee must comply with all requirements and specifications contained within the License Agreement, the most current version of this document, and the most current version of the Interface Developers Guide unless explicitly allowed, prohibited, or modified by USPS in writing.

User Guides
How the Educational/Seasonal Indicator is used

New DSF2 Educational/Seasonal Indicator.

Fact Sheets
Licensing Fees

This document contains information about licensing fees for USPS® Licensed Products.

Related Products


The DPV® Product identifies whether a ZIP + 4® coded address is currently represented in the USPS® delivery file as a known address record. It also allows users to confirm known USPS addresses, as well as, identify potential addressing issues that may hinder delivery.

ZIP + 4® Product

The ZIP + 4® Product is a base reference file that can be accessed by an application to assign the correct ZIP + 4® Code associated with a physical address.


For more information on the DSF licensing and certification process, please contact the Move Update Support Department at 1-800-589-5766.