What is trailing nexus?

Most states make you keep filing for a while after you drop below their threshold. California runs through the next full calendar year. Texas uses a rolling twelve months. We track each state's rule so you cancel on the right date, not too early.

Will I get in trouble for canceling a permit?

Not if you do it in the right order. We file every outstanding and final return first, then guide the cancellation. The real risk is canceling early or skipping a final return, which is exactly what we prevent.

Which platforms do you support?

Amazon, Shopify and WooCommerce, with BigCommerce, Etsy, Walmart and eBay supported through manual entry. You can also enter your states by hand on any platform.

Do you file my returns?

Yes. During the wind-down we file the zero-dollar returns so nothing lapses, and once you're deregistered in a state there's nothing left to file.

How is this different from Avalara or TaxJar?

They help you register and file more. We help you deregister and file less. We only charge for the states you keep.

No. TrailingZero is software that flags deregistration opportunities and handles filings. For complex situations we tell you when to bring in your accountant.

Is TrailingZero live?

Yes. Free audits are live now — run yours in minutes. Connect a store read-only or enter your registered states by hand to see which you can cancel and what it saves.

Do I need to collect sales tax in Connecticut?

Only once you have nexus: physical presence, or crossing $100,000 in sales and 200 transactions over 12-month period ending September 30. Under that, with no physical presence, you generally don't.

Do marketplace sales count toward the Connecticut threshold?

Yes — even though the marketplace collects the tax, those sales count toward whether you must register.

No. This page is general education built from public sources and the rules change often. Confirm your specific situation with the state's tax authority or your accountant before you register or deregister.

Registration guide

Should I register for sales tax in Connecticut?

Before you register for sales tax in Connecticut, check whether you actually have to. Registering when you don't owe just adds a recurring return — here's exactly when Connecticut requires it.

By John DoeReviewed by Jane Doe, CPAUpdated June 2026How we verify

Verify before you act

Sources currently disagree on some details for this state — especially the trailing-nexus window and how to deregister — so we've flagged it for manual review. Treat this page as a starting point and confirm with Connecticut Department of Revenue Services (DRS) or a tax professional before you register or deregister.

Economic threshold: $100,000 in sales and 200 transactions
Measured over: 12-month period ending September 30
In effect since: December 2018
Marketplace sales count?: Yes
Registration fee: $100

Source: Connecticut Department of Revenue Services (DRS)

When you must register

You must register in Connecticut if you have physical presence there (inventory, staff, an office) or you cross $100,000 in sales and 200 transactions (12-month period ending September 30). Below that, with no physical presence, you generally don't have to.

Nexus & savings calculator

Estimate whether you still have nexus in Connecticut — and what canceling could save.

State

Annual sales into Connecticut

Transactions (orders) per year

I have physical presence hereFBA/3PL inventory, an employee, or an office in Connecticut

Filing frequency

Cost per return

Physical presence
Sales over $100,000
Over 200 transactions

Likely eligible to cancel

Based on these numbers you likely no longer have nexus in Connecticut. You can usually deregister after clearing the trailing-nexus window and filing your final return.

Trailing nexus: Connecticut has limited or no trailing-nexus window — you can generally deregister once your nexus has ended and final returns are filed.

You could stop paying

$600/ yr

How to cancel in Connecticut →

Estimate only — general education, not tax advice. Confirm with Connecticut's tax authority before you register or deregister.

When registration is required in Connecticut

Connecticut requires registration once you cross $100,000 in sales and 200 transactions, measured over 12-month period ending September 30. Connecticut still counts transactions: crossing 200 transactions creates nexus even on modest revenue.

Physical presence registers you regardless of sales. Storing inventory in Connecticut (including Amazon FBA fulfillment centers) creates physical nexus regardless of sales volume.

The marketplace nuance most sellers miss

If you sell only through a marketplace like Amazon or Etsy, the marketplace facilitator generally collects and remits Connecticut tax for you, so you may not need your own permit. But those facilitated sales still count toward your threshold — so direct sales (your own Shopify/WooCommerce store) can still push you over.

How to register in Connecticut

Don't over-register

Most over-registered sellers signed up defensively across many states after 2018. If you're under Connecticut's threshold with no physical presence, registering early just creates a recurring zero-dollar return. Register when you truly must — and track the states where you can stop.

Where TrailingZero fits

TrailingZero connects to your store read-only, maps where you actually have nexus state by state, and flags when you genuinely cross Connecticut's threshold — and where you've already dropped below and can deregister. During any wind-down it can file the zero-dollar returns so nothing lapses — and you only pay for the states you genuinely keep. Run a free audit anytime; this page is free education either way.

Connecticut Should I register FAQ

Do I need to collect sales tax in Connecticut?: Only once you have nexus: physical presence, or crossing $100,000 in sales and 200 transactions over 12-month period ending September 30. Under that, with no physical presence, you generally don't.
Does Connecticut still count transactions?: Connecticut still counts transactions: crossing 200 transactions creates nexus even on modest revenue.
Do marketplace sales count toward the Connecticut threshold?: Yes — even though the marketplace collects the tax, those sales count toward whether you must register.
Is this tax advice?: No. This page is general education built from public sources and the rules change often. Confirm your specific situation with the state's tax authority or your accountant before you register or deregister.

See what you can stop paying in Connecticut

Run a free audit and see which registrations you can drop — in minutes, no card required.

Start free →Free audit · no card required.

Other states

See all states →

Sources

Primary sources reviewed for this page. Data current as of June 2026.

TrailingZerois software, not a CPA or law firm, and this page is general education — not tax or legal advice. State rules and thresholds change frequently; confirm your situation with the state's tax authority or your accountant before you register or deregister. See how we research and review this data in our editorial & accuracy policy.