Connecticut sales tax: rates, nexus & Department of Revenue Services filing
Connecticut sales tax: 6.35% state base, combined rates 6.35% statewide (no local add-on), $100,000 AND 200+ transactions nexus. No local sales tax — flat 6.35% statewide.
Connecticut at a glance
| Field | Value |
|---|---|
| State base rate | 6.35% |
| Combined rate range | 6.35% statewide (no local add-on) |
| Economic nexus | $100,000 AND 200+ transactions nexus |
| Lookback period | preceding 12 months |
| Marketplace facilitator | Yes — facilitator collects on 3P sales |
| SaaS taxable? | Yes — taxable — Computer and data-processing services taxed at a reduced 1% rate. |
| Sourcing rule | Destination (rate at buyer's location) |
Connecticut-specific quirks worth knowing
- No local sales tax — flat 6.35% statewide.
- AND-test on economic nexus — both $100k AND 200 transactions required.
- Computer/data-processing services taxed at 1% rather than 6.35% (legacy Section 12-407 carve-out).
- Luxury goods (clothing/footwear ≥ $1,000, certain jewelry) taxed at a higher 7.75% rate.
Authoritative source
Connecticut tax rules change every legislative session. Always verify the current position with the official source before filing:
How HelloBooks does this
HelloBooks handles every Connecticut-specific quirk listed above — base rate + local components per ship-to ZIP, the $100,000 nexus tracker, marketplace separation, Connecticut Department of Revenue Services filings, and use tax reconciliation.
- 1
Register with the Connecticut Department of Revenue Services
Apply for a Connecticut sales tax permit (or registration) on the Connecticut Department of Revenue Services portal at https://portal.ct.gov/DRS/Sales-Tax. You'll be assigned a filing frequency at registration. Enter the permit number and frequency into HelloBooks.
- 2
Tag invoices for Connecticut delivery
When you create invoices for customers shipping to Connecticut, HelloBooks separates direct sales (you remit) from marketplace-facilitator sales (Amazon, Etsy, etc. remit). Both count toward your Connecticut nexus threshold; only direct sales hit your return.
- 3
Apply the right combined rate per ship-to address
On Pro and above, HelloBooks computes the rate per ship-to address through Avalara AvaTax — state 6.35% + the right local components (city / county / special district) up to the maximum combined rate of 6.35% statewide (no local add-on), kept current as the Connecticut Department of Revenue Services updates rates. On the Free Plan you apply manual per-state rates. Sourcing follows the buyer's location.
- 4
Build and file the return on the assigned schedule
HelloBooks builds the period's return from tagged sales — taxable, exempt, marketplace-facilitator gross, and use-tax-due lines. Review the working paper, file directly on the Connecticut Department of Revenue Services portal, and mark paid in HelloBooks.
- 5
Reconcile use tax on out-of-state purchases
HelloBooks tracks vendor bills where no sales tax was collected and computes the Connecticut use tax owed at the destination rate. Use tax flows to the same return as a separate line item — keeping you audit-ready on the often-forgotten compliance surface.
Frequently asked questions
What is the Connecticut sales tax rate?
6.35% statewide. Combined rates including local add-ons range 6.35% statewide (no local add-on). The exact rate at a buyer's address depends on city, county, and special-district overlays — pull the current rate from the Connecticut Department of Revenue Services.
What is the Connecticut sales tax economic nexus threshold?
$100,000 AND 200+ transactions nexus, evaluated against the preceding 12 months. Once you cross the threshold, register with the Connecticut Department of Revenue Services on the next business cycle and start collecting on the first sale after registration takes effect.
Does Connecticut tax SaaS?
Yes. Connecticut treats SaaS as taxable. Computer and data-processing services taxed at a reduced 1% rate.
Is Connecticut destination-sourced or origin-sourced?
Destination (rate at buyer's location) for in-state sales. Inter-state sales into Connecticut from out-of-state sellers are always destination-sourced regardless of the seller's state.
Does Connecticut have a marketplace facilitator law?
Yes. Marketplace facilitators (Amazon, Etsy, eBay, Walmart) collect and remit Connecticut sales tax on third-party seller transactions. You still track marketplace sales toward your own nexus threshold, but the marketplace handles the remittance.
Where can I file Connecticut sales tax returns?
Connecticut Department of Revenue Services runs the filing portal at https://portal.ct.gov/DRS/Sales-Tax. Filing frequency (monthly / quarterly / annual) is assigned at registration based on expected liability.
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Authoritative sources
US tax rules change every filing season. Always verify the current position with the official sources below before filing.
- IRS — irs.govInternal Revenue Service. Forms, publications, due dates, and current-year thresholds for federal income tax, payroll tax, and 1099 reporting.
- IRS — Forms & InstructionsCanonical PDF forms (W-4, W-9, 1099-NEC, 1040-ES, 941, 940, W-2, W-3) with current-year instructions.
- SSA — Business Services OnlineSocial Security Administration portal for W-2 / W-3 e-filing, EIN verification, and AccuWage validation.
- Streamlined Sales Tax — streamlinedsalestax.orgMulti-state Streamlined Sales and Use Tax Agreement (SSUTA) — registration in 24 SST member states with one application.
- Tax Foundation — Sales Tax & NexusIndependent state-by-state research on sales tax rates, economic nexus thresholds, and franchise / margin tax structures.
Run all of this on autopilot in HelloBooks
US sales tax, state franchise tax, and quarterly estimated tax workflows are built into the free plan. Plaid connects 11,000+ US banks so transactions land in your books automatically. 1099 generation and Gusto-backed payroll are in private preview — ask us for access.
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