How do I register as a Sole Proprietor?

Individuals who choose to do business under an Assumed Business Name may be referred to as a "sole proprietor." A sole proprietor is a business owned by one individual.

To Register an Assumed Business Name (ABN/DBA):
Please visit sosmt.gov or use the following portal link: https://biz.sosmt.gov/.

1. From sosmt.gov, scroll down to view/click on the Online Filing Portal.
2. On the portal home page, click the “Login” button in the upper right corner, then “Log in” on the left, and enter your username and password.
3. • If you need to create an account, click “Create an Account” on the right-hand side.
3. Once you are logged in, click Register a Business or Forms on the left.
4. • Registration for an Assumed Business Name (ABN/DBA) will be on the top left-hand side.
   • The form will open, and you will complete the application online. Please read all the instructions and ensure that you complete every form item marked with a red asterisk. Click on the Question Mark icon to see more information about the fields on each page.
4. Once you have completed the application online, click the “FILE ONLINE” button and make your payment with either a credit/debit card or an e-check.
5. • Registration of an assumed business name is $20 and must be renewed every five years.

Updated on: 08/04/2026