Sole proprietorship vs LLC in Connecticut: which costs less (2026)

At $100,000 profit in Connecticut, a sole proprietorship costs $25,901 a year in tax and fees and a single-member LLC costs $25,952. On these figures a single-member LLC does not cost less at any profit up to $500,000.

+$51 a year

more for a single-member LLC than a sole proprietorship in Connecticut, at these numbers.

With these settings the switch does not pay at any profit from $10,000 to $500,000. Setting up costs $120 once in state filing fees.

Connecticut, 2026: $100,000 profit, single filer

Item	Sole prop	LLC	Change
Self-employment taxirs.gov, 2026 rates	$14,130	$14,118	−$12
Federal income taxirs.gov, 2026 rates	$8,235	$8,222	−$13
State income taxportal.ct.gov, checked Oct 20, 2026	$3,536	$3,532	−$4
Annual Reportbusiness.ct.gov, checked Oct 20, 2026	$0	$80	+$80
Yearly cost	$25,901	$25,952	+$51

What these figures count

State income tax, and state taxes on the business itself: franchise, LLC, S corp, gross receipts and excise taxes.
Social Security and Medicare on both sides of an owner salary, federal unemployment tax and the state's new-employer rate.
The 20% qualified business income deduction with its income limits and the professional-service rule.
Yearly report fees, and a cost you can change for payroll and the business tax return.

Many S corp calculators leave out state taxes and the QBI deduction, which can make the election look better than it is.

Yearly cost at each profit level

Profit	Sole prop	LLC	Difference
$30,000	$5,511	$5,571	+$60
$50,000	$10,898	$10,956	+$58
$75,000	$17,754	$17,811	+$57
$100,000	$25,901	$25,952	+$51
$150,000	$43,821	$43,873	+$52
$200,000	$62,433	$62,491	+$58
$300,000	$107,474	$107,497	+$23

Federal and Connecticut tax and fees, single filer, revenue 1.5 times profit, default salary for S and C corps. "Difference" is Single-member LLC minus Sole proprietorship.

What the switch takes in Connecticut

File the Certificate of Organization with the state: $120 (fee).
Get an EIN from the IRS (free, online) and open a business bank account in the new name.
Federal return each year: Schedule C with your Form 1040, due April 15.
State upkeep each year: Annual Report, $80 a year, due Between January 1 and March 31 each year.

What changes between the two

A single-member LLC is a disregarded entity for income tax: it files the same Schedule C and pays the same self-employment and income tax as a sole proprietor. What it adds in Connecticut is $120 to form and Annual Report, $80 a year.

What it gives: business debts and claims stay with the LLC, as long as business and personal money stay apart. Many banks, clients and platforms ask for one. It is also the step before an S corp election, with no new company needed.

Questions

Does an LLC save tax over a sole proprietorship in Connecticut?

No. It pays the same federal and Connecticut income tax and self-employment tax, plus the state's LLC fees.

What does an LLC cost to start in Connecticut?

$120 to file the Certificate of Organization.

How much does it save at $100,000 in Connecticut?

Nothing. Single-member LLC costs $51 a year more ($25,952 against $25,901).

More for Connecticut

Common cases in Connecticut

Other states