Using the state rate and ignoring local tax
The state rate is 6.35% but the average customer pays 6.35%. Under-collecting leaves you funding the difference out of your own margin.
USD · 6.35% average combined rate · Reviewed September 2026
Connecticut Invoice Generator & Sales Tax Guide
Create a Connecticut Invoice and Check the Connecticut Tax Position
Build a professional invoice for a customer in Connecticut below — free, no account, no watermark. Set your own tax rate, add line items and download a clean PDF.
Connecticut levies no local sales taxes, so one statewide rate applies everywhere — though certain categories carry their own special rates set in statute.
Connecticut sales tax rates
Connecticut charges sales and use tax at 6.35% statewide. There are no local add-ons, so one rate applies across the state.
| Statewide rate | 6.35% |
|---|---|
| Average local add-on | 0.00% |
| Highest local add-on tracked | 0.00% |
| Average combined rate | 6.35% |
| Rank by combined rate | 33rd highest of 50 states |
Local rates in Connecticut
Connecticut does not allow local sales taxes. The 6.35% state rate applies in every city and county, which removes the address-lookup problem that sellers face in most other states.
Special rates can still apply to particular categories — lodging, prepared food, vehicle rental and similar — so check the category as well as the rate.
What to put on a Connecticut invoice
- The word Invoice and a unique invoice number
- Your business name, address, email and phone
- The customer's legal name and Connecticut billing address
- Invoice date and a calendar due date, not just Net 30
- A line for each item or service with quantity and rate
- Any sales and use tax shown on its own line with the rate used
- How to pay — ACH details, check payee or a payment link
- A purchase order number where the customer issued one
- Your state tax permit number where the state expects it
- A reference to an exemption or resale certificate on exempt sales
Registering and filing in Connecticut
Sellers with a physical presence in Connecticut — premises, staff, stock or regular on-site work — generally register with the Connecticut Department of Revenue Services before their first taxable sale. Remote sellers register once their sales into the state cross the state's economic nexus threshold.
Filing frequency is set by the state and usually depends on how much tax you collect: larger collectors file monthly, smaller ones quarterly or annually. The Connecticut Department of Revenue Services sets and notifies your frequency — do not assume it stays the same as your volume grows.
We deliberately do not publish thresholds, filing deadlines or penalty amounts on this page. Those numbers change, and the only copy worth relying on is the one on the state's own site, linked below.
Exempt sales and certificates
Resale, manufacturing, non-profit and government exemptions all exist in Connecticut, and each one depends on a valid certificate from the buyer, not on the buyer's word. Collect the certificate before you issue a zero-tax invoice.
Reference the certificate on the invoice rather than silently leaving tax off. A tax line of $0.00 with a note explaining why is far easier to defend in an audit than an invoice with no mention of tax at all.
Example Connecticut invoice
A contractor billing a Connecticut customer for equipment and labour, showing how the tax line sits under the subtotal.
| Description | Qty | Rate | Amount |
|---|---|---|---|
| Equipment supplied and installed | 1 | $1,600.00 | $1,600.00 |
| On-site labour | 8 | $100.00 | $800.00 |
| Subtotal | $2,400.00 | ||
| Connecticut sales and use tax at the 6.35% average combined rate | $152.40 | ||
| Total due — Net 30 | $2,552.40 | ||
Common Connecticut invoicing mistakes
Charging tax without being registered
Collecting sales and use tax before you are registered creates a liability with no account to remit it to, and the customer cannot reclaim it.
Assuming services are treated like goods
Taxability of services varies widely between states and within them. Confirm the treatment of your specific service with the Connecticut Department of Revenue Services rather than copying what a supplier in another state does.
Leaving the due date implied
Write both the terms and a calendar date. In a corporate payment run, an ambiguous due date always resolves in the payer's favour.
Filing the certificate nowhere
Exemption and resale certificates are what justify a zero-tax invoice years later. Store them alongside the invoice, not in an inbox.
Sending to your day-to-day contact only
Your contact commissioned the work; a different inbox pays for it. Ask for the accounts payable address at the start.
Connecticut invoicing FAQs
What is the sales tax rate in Connecticut?
The statewide rate is 6.35%. Local jurisdictions add 0.00% on average and up to 0.00% where local taxes are highest, giving an average combined rate of 6.35% — the 33rd highest average combined rate in the country. Figures are from the Tax Foundation's midyear 2026 table; always confirm the rate for your customer's exact address with the Connecticut Department of Revenue Services.
Do I have to charge Connecticut sales and use tax on my invoices?
Only if you are registered in Connecticut and what you sell is taxable there. Registration is triggered by physical presence or by crossing the state's economic nexus threshold for remote sellers. Taxability of services in particular varies, so check the position for your specific work with the Connecticut Department of Revenue Services before adding a tax line.
Does Connecticut have local city or county sales taxes?
No. Connecticut has no local sales taxes, so the 6.35% state rate applies everywhere in the state.
Is a specific invoice format required in Connecticut?
There is no prescribed commercial invoice template in Connecticut. What matters is that the invoice identifies both parties, describes the supply, shows the amount due, shows any sales and use tax separately, and can be reconciled with your returns and records.
Where do I register for Connecticut sales and use tax?
Through the Connecticut Department of Revenue Services, which runs registration, filing and rate lookups for Connecticut. Its website is linked in the official sources section on this page.
Can I invoice a Connecticut customer from another state or country?
Yes — the invoice itself is the same document. The question is whether your sales into Connecticut create a registration obligation there. Remote sellers can be required to register once they exceed the state's economic nexus threshold, so track your sales by state.
Official sources
Last reviewed September 2026.
- Connecticut Department of Revenue Services
The primary authority for Connecticut registration, rates, filing and exemption rules.
- Tax Foundation — State and Local Sales Tax Rates, Midyear 2026
Secondary source for the statewide, average local and combined rate figures shown above.
- Federation of Tax Administrators — state tax agencies
Directory used to locate each state's official tax agency.
- IRS — small business and self-employed tax center
Federal guidance on business income, record-keeping and Form W-9.
Related tools and reading
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