Starting a Side Business in CT? Tax Checklist
Starting a side business in Connecticut? This side hustle tax checklist covers self-employment tax, quarterly estimates, CT registration and the records to keep from day one. Checked November 3, 2026.
For general education only. Not tax, legal, insurance, or investment advice, and not a promise of any result. Tax rules and due dates change, so confirm with the IRS (irs.gov), the CT Department of Revenue Services (portal.ct.gov/DRS) or your town before you act, and ask your tax preparer about your own situation.
What changes for your taxes
- Self-employment tax: 15.3% on 92.35% of net earnings once net earnings reach $400 (IRS).
- Estimated taxes: generally due if you'll owe $1,000 or more; raising your paycheck withholding is another option (IRS).
- Sales tax: if you sell taxable goods or services, register with CT DRS in myconneCT (CT DRS).
What to do before December 31, 2026
- To do Open a separate account for the business.
- To do Track every expense and business mile from the start.
- To do Make a Jan 15, 2027 estimated payment if your side income is meaningful, or adjust your W-4 now.
- To do Collect 1099s in January, and report all income even without a form.
The Connecticut side
- Using a trade name? File it with your town clerk ($20). See our CT Business Launch Wizard for a personalized list.
Related free tools: What did I forget? CT tax checker · Tax deadline reminders · Tax checklists
← Life Event Tax Guide · Just Got Married · Just Had a Baby · Buying Your First Home · Lost Your Job · When a Parent Dies · Getting Divorced · Retiring · Moving to or From CT
Frequently asked questions
Do I have to pay taxes on a side hustle?
Yes, profit from a side business is taxable income, and self-employment tax applies once net earnings reach $400.
Do I need to make quarterly payments for side income?
Generally if you'll owe $1,000 or more when you file. Increasing withholding at your day job can cover it instead.
Do I need to register my side business in Connecticut?
If you sell taxable goods or services you register with CT DRS. A trade name is filed with your town clerk, and an LLC is formed with the Secretary of the State.
Sources (Checked November 3, 2026)
For general education only. Not tax, legal, insurance, or investment advice, and not a promise of any result. Tax rules and due dates change, so confirm with the IRS (irs.gov), the CT Department of Revenue Services (portal.ct.gov/DRS) or your town before you act, and ask your tax preparer about your own situation.
Life just changed and you want your taxes handled right? We can help you sort out what applies to you.
Or call (475) 242-7941. Services are priced by quote.
Enhance Finance is a small-business finance practice serving Connecticut.