Connecticut's Sales Tax Deadline Isn't January 1 — It's Today
Most sales tax nexus conversations happen in December or January, timed to the calendar year most states use. Connecticut runs on a completely different clock, and if you weren't watching for it, today matters more than you might realize.
A Threshold Measured on Its Own Calendar
Connecticut measures economic nexus over a 12-month period running from October 1 through September 30, not the calendar year. If your Connecticut gross receipts and transaction count both crossed the threshold during that window, which just closed, your registration obligation begins today, October 1.
The Threshold Itself: a Genuine AND, Not an OR
Connecticut requires $100,000 in gross receipts AND 200 separate transactions into the state, both within that same 12-month window. Crossing only one side doesn't create nexus. This is a real, meaningful distinction from most comparable states, where either condition alone is usually enough. Connecticut shares this AND structure with only one other state in Regulens' coverage: New York.
Marketplace sales count toward both thresholds, even when a marketplace facilitator is the one actually collecting tax on that portion. A seller who assumes their Shopify-direct sales are the only thing that matters could be underestimating where they actually stand.
Why the October Timing Catches Sellers Off Guard
A seller who checks their nexus exposure every January, in step with most other states, has already missed Connecticut's actual measurement window by three months. The period that just determined today's obligation closed on September 30, not December 31. Checking once a year, on the wrong calendar, can mean discovering a Connecticut obligation months after it technically began.
What Happens If You've Crossed It
Connecticut requires sellers to begin collecting tax from the date nexus was actually triggered, not the date of registration. The obligation to collect doesn't wait for paperwork to catch up, which makes the three-month gap between threshold-crossing and today's deadline worth taking seriously rather than treating as a soft target date.
Check Your Connecticut Position Today
All information in this article is sourced from the Connecticut Department of Revenue Services and independent verification from TaxCloud, Sovos, and Discern's published Connecticut nexus guidance. Regulens is informational only and this article is not legal advice. Speak to a licensed tax professional about your specific compliance situation.
Regulens tracks Connecticut's unique AND-threshold structure as part of its full 50-jurisdiction tax nexus coverage.
Free to check, takes three minutes, no credit card needed. Not legal advice. Informational only.
Check your store's Connecticut tax readiness at getregulens.com
Further Reading
Four States Now Ban Selling Your Customers' Exact Location — Is Yours Next
Virginia, Connecticut, Maryland, and Oregon have each independently banned the sale of precise geolocation data within the same general stretch of time. A pattern like this rarely stays confined to four states for long.
Utah's New Tax Has Nothing to Do With Nexus Thresholds — And That's the Point
As of this month, Utah taxes a specific category of digital content at 2%, tied to age-verification requirements. It's a genuinely different kind of obligation than the nexus thresholds most sellers are used to tracking.