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Trailing nexus

Trailing nexus in Connecticut

"Trailing nexus" is the duty to keep filing in Connecticut for a while after you drop below the threshold. Getting this window wrong is the single most common deregistration mistake — here's Connecticut's rule.

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.

Has trailing nexus?
Minimal / none
Approx. duration
Can deregister below threshold?
Yes, after the window
Tax authority
Connecticut Department of Revenue Services (DRS)

Source: State rule

Connecticut trailing nexus

Connecticut has little or no formal trailing-nexus window — once your nexus ends and final returns are filed, you can generally deregister.

What trailing nexus means

When you drop below Connecticut's threshold, the obligation doesn't end instantly. Most states make you keep the registration active and keep filing — even $0 returns — for a defined window. That window is "trailing" (or "sticky") nexus.

Connecticut's trailing-nexus rule

Connecticut has no specified trailing nexus policy. There is no published DRS guidance on how long a business must maintain obligations after dropping below the economic nexus threshold. Connecticut measures thresholds on the 12-month period ending September 30; if a seller no longer meets both thresholds on September 30, there is no statutory obligation to continue collecting, but DRS has not issued a formal trailing nexus rule.

No explicit statutory restriction on deregistration after falling below threshold, but the absence of a formal trailing nexus policy creates uncertainty. Sellers should confirm with DRS or a tax advisor before canceling.

Why it matters for canceling

Canceling the day you drop below the threshold — or skipping a required final return — is exactly what triggers penalties. Clear Connecticut's window first, file every return due during it, then close the account.

Where TrailingZero fits

TrailingZero connects to your store read-only, maps where you actually have nexus state by state, and computes Connecticut's exact trailing-nexus end date so you cancel on the right day, not too early. 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 Trailing nexus FAQ

How long is trailing nexus in Connecticut?
Connecticut has little or no formal trailing-nexus window.
Can I stop filing in Connecticut right after I drop below the threshold?
In Connecticut, once your nexus has ended and final returns are filed, you can generally stop.
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.

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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.