Here you will find an outline of the Boundary and Annexation Survey (BAS) participation process. The other pages in this section, found on the left-hand side of the screen, contain additional resources and detailed information on various aspects of BAS, including response methods, state and county agreements, and related programs. If you have questions regarding any of this information, please review the FAQs or Contact Us.

The online Annual Response Form will walk you through each of the steps in the BAS participation process outlined below.

1.  Review your boundary using one of the following methods:

• TIGERweb
  
• 2025 BAS Partnership Shapefiles
• 2025 BAS Maps

2.  Complete the Annual Response Form. Within the form you will review and update your contact information and report whether you have boundary changes to submit through BAS. In addition, you can review your government name and register for a webinar.

If you determine you do not have boundary changes, there are no additional steps after completing the Annual Response Form.

3.  Create your BAS submission. If you determine you do have boundary changes, you will select a response method on the Annual Response Form. Information on the available response methods can be found on the response methods webpage. After submitting the form, you will use your chosen response method to create your BAS submission. The available response methods help ensure the Census Bureau receives a standardized submission that can be processed in a uniform manner. Step-by-step instructions for each response method can be found in the corresponding guide on the How-to Guides webpage.

4.  Submit your boundary changes to the Census Bureau.

• If you created your submission using the BAS Partnership Toolbox or GUPS, use the Secure Web Incoming Module (SWIM) to securely transfer your changes to the Census Bureau. First time SWIM users: A token is required to register for a new account. Contact geo.bas@census.gov with your request and allow five business days for delivery of your SWIM token to your email account.
• GUPS Web submissions will be submitted directly to the Census Bureau using the GUPS Web application (not SWIM).
• If you created your submission using paper maps, use the provided pre-paid envelope to mail your updated maps to the Census Bureau.