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Connecticut sales and use tax guide

All you need to know about sales tax in the Constitution State

Learn about sales tax automation

Introducing our Sales Tax Automation 101 series. The first installment covers the basics of sales tax automation: what it is and how it can help your business.

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Sales tax 101

Sales tax is a tax paid to a governing body (state or local) on the sale of certain goods and services. Connecticut first adopted a general state sales tax in 1947, and since that time, the rate has risen to 6.35%. In many states, localities are able to impose local sales taxes on top of the state sales tax. However, there are no local sales taxes in Connecticut.


As a business owner selling taxable goods or services, you act as an agent of the state of Connecticut by collecting tax from purchasers and passing it along to the appropriate tax authority. Sales and use tax in Connecticut is administered by the Department of Revenue Services (DRS).


Any sales tax collected from customers belongs to the state of Connecticut, not you. It’s your responsibility to manage the taxes you collect to remain in compliance with state and local laws. Failure to do so can lead to penalties and interest charges.


When you need to collect Connecticut sales tax


In Connecticut, sales tax is levied on the sale of tangible goods and some services. The tax is collected by the seller and remitted to state tax authorities. The seller acts as a de facto collector.


To help you determine whether you need to collect sales tax in Connecticut, start by answering these three questions:

  1. Do you have nexus in Connecticut?
  2. Are you selling taxable goods or services to Connecticut residents?
  3. Are your buyers required to pay sales tax?


If the answer to all three questions is yes, you’re required to register with the state tax authority, collect the correct amount of sales tax per sale, file returns, and remit to the state.


Failure to collect Connecticut sales tax


If you meet the criteria for collecting sales tax and choose not to, you’ll be held responsible for the tax due, plus applicable penalties and interest.


It’s extremely important to set up tax collection at the point of sale — it’s near impossible to collect sales tax from customers after a transaction is complete.

Sales tax nexus

The need to collect sales tax in Connecticut is predicated on having a significant connection with the state. This is a concept known as nexus. Nexus is a Latin word that means “to bind or tie,” and it’s the deciding factor for whether the state has the legal authority to require your business to collect, file, and remit sales tax.


Nexus triggers


Sales tax nexus in all states used to be limited to physical presence: A state could require a business to register and collect and remit sales tax only if it had a physical presence in the state, such as employees or an office, retail store, or warehouse.


In June 2018, the Supreme Court of the United States overruled the physical presence rule with its decision in South Dakota v. Wayfair, Inc. States are now free to tax businesses based on their economic and virtual connections to the state, or economic nexus.


While physical presence still triggers a sales tax collection obligation in Connecticut, it’s now possible for out-of-state sellers to have sales tax nexus with Connecticut.


Out-of-state sellers


Out-of-state sellers with no physical presence in a state may establish sales tax nexus in the following ways:


Affiliate nexus:
Having ties to businesses or affiliates in Connecticut. This includes, but isn’t limited to, the design and development of tangible personal property (goods) sold by the remote retailer, or solicitation of sales of goods on behalf of the retailer.


Click-through nexus:
 Connecticut law may establish nexus for certain out-of-state retailers that compensate Connecticut residents or businesses for referring customers through links, websites, or other solicitation arrangements.


However, economic nexus and marketplace facilitator laws now govern most remote seller sales tax obligations. Businesses should review current Connecticut DRS guidance to determine whether separate affiliate or referral nexus rules apply to their activities.


Economic nexus:
 A remote seller is generally required to register for Connecticut sales and use tax and collect tax on taxable sales into the state if, during the previous 12-month period, the seller:
 

  • has more than $100,000 in gross retail sales delivered into Connecticut; and
  • makes 200 or more retail transactions into the state.


Remote sellers that meet these economic nexus thresholds are generally considered retailers engaged in business in Connecticut and must comply with the state’s sales and use tax laws.


Inventory in the state:
 Storing property for sale in the state. This includes merchandise owned by Fulfillment by Amazon (FBA) merchants and stored in Connecticut in a warehouse owned or operated by Amazon.


Marketplace sales:
 Marketplace facilitators that facilitate taxable retail sales into Connecticut are generally responsible for collecting and remitting Connecticut sales tax on behalf of marketplace sellers. As a result, many marketplace sellers are not required to separately collect Connecticut sales tax on sales processed through a marketplace facilitator. However, marketplace sellers may still have separate registration or filing obligations depending on their activities in the state.


Trade shows:
 Attending conventions, trade shows, or similar events in Connecticut may create sales tax nexus depending on the nature and extent of the business activities conducted in the state.


You may not establish nexus if all the following are true:
 

  • Your activities in Connecticut are limited to convention or trade show participation;
  • Your activities are limited to displaying products or soliciting orders;
  • Orders are approved and fulfilled from outside Connecticut; and
  • You do not otherwise engage in business activities in the state that create nexus.


If you have sales tax nexus in Connecticut, you’re generally required to register with the Connecticut Department of Revenue Services (DRS) and charge, collect, and remit the appropriate tax to the state.


For more information, see the Connecticut State Department of Revenue Service - Sales and Use Tax Information webpage.


Non-collecting seller use tax reporting


The Connecticut Department of Revenue Services requires non-collecting sellers to notify customers about their potential use tax liability, provide customers with an annual purchase summary, and provide the state with a customer information report. See the Connecticut State Department of Revenue Service - Sales and Use Tax Information webpage for more information.


Trailing nexus


Sales tax nexus can continue even after a business ceases the activities that originally created nexus in the state. This concept is commonly referred to as trailing nexus. Connecticut does not currently impose a specifically defined trailing nexus period for sales tax purposes. However, businesses that previously established nexus may continue to have filing obligations until their Connecticut sales tax account is formally closed with DRS.


Fulfillment by Amazon (FBA)


If you’re an active Amazon seller and you use Fulfillment by Amazon (FBA), you need to know where your inventory is stored and if its presence in a state will trigger nexus. FBA sellers can also download an Inventory Event Detail Report from Amazon Seller Central to identify inventory stored in Connecticut.


If you sell taxable goods to Connecticut residents and have inventory stored in the state, you likely have nexus and an obligation to collect and remit tax. To begin to understand your unique nexus obligations, check out our free economic nexus tool or consult with a trusted tax advisor.


Sourcing sales tax in Connecticut: which rate to collect


In some states, sales tax rates and sourcing rules are based on the seller’s location (origin-based sourcing). In others, sales tax is based on the purchaser’s location and where the product is delivered (destination-based sourcing).


Connecticut is generally a destination-based sourcing state. This means sellers are generally responsible for applying the sales tax rate based on the delivery location of the taxable product or service. For shipped goods, sellers generally apply the applicable Connecticut sales tax rate using the customer’s delivery address.

Getting registered

After determining you have sales tax nexus in Connecticut, you need to register with the proper state authority and collect, file, and remit sales tax to the state. We get a lot of questions about this and recognize it may be the most difficult hurdle for businesses to overcome. Avalara Licensing can help you obtain your Connecticut business license and sales tax registration.


How to register for a Connecticut selle’s permit


You can register for a Connecticut seller’s permit online through the DRS. To apply, you’ll need to provide the DRS with certain information about your business, including but not limited to:
 

  • Business name, address, and contact information
  • Federal EIN number
  • Date business activities began or will begin
  • Projected monthly sales
  • Projected monthly taxable sales
  • Products to be sold


Cost of registering for a Connecticut seller’s permit


Connecticut requires businesses registering for a Sales and Use Tax Permit to pay a registration fee. Businesses should review current Connecticut Department of Revenue Services (DRS) guidance for the latest fee amounts, renewal requirements, and account maintenance procedures.


Registered businesses are responsible for keeping their tax accounts active and ensuring their business information remains current with DRS.


Acquiring a registered business


You must register with the Department of Revenue Services if you acquire an existing business in Connecticut. The state requires all registered businesses to have the current business owner’s name and contact information on file.


Streamlined Sales Tax (SST)


The Streamlined Sales and Use Tax Agreement (SSUTA), or Streamlined Sales Tax (SST), is an effort by multiple states to simplify the administration and cost of sales and use tax for remote sellers. Remote sellers can register in multiple states at the same time through the Streamlined Sales Tax Registration System (SSTRS).


Connecticut is not an SST member state.

Collecting sales tax

Once you’ve successfully registered to collect Connecticut sales tax, you’ll need to apply the correct rate to all taxable sales, remit sales tax, file timely returns with the Department of Revenue Services, and keep excellent records. Here’s what you need to know to keep everything organized and in check.


How you collect Connecticut sales tax is influenced by how you sell your goods:

Brick-and-mortar store:
Have a physical store? Brick-and-mortar point-of-sale solutions allow users to set the sales tax rate associated with the store location. New tax groups can then be created to allow for specific product tax rules.


Hosted store:
Hosted store solutions like Shopify and Squarespace offer integrated sales tax rate determination and collection. Hosted stores offer sellers a dashboard environment where Connecticut sales tax collection can be managed.


Marketplace:
 Marketplaces like Amazon and Etsy generally calculate, collect, and remit sales tax on taxable transactions they facilitate under marketplace facilitator laws. In these cases, the marketplace is typically responsible for sales tax compliance on covered sales, while sellers should confirm which transactions are included in marketplace reporting and which remain their responsibility.


Mobile point of sale:
 Mobile POS systems may use the business location, transaction settings, or entered address information to determine the appropriate sales tax rate. These systems can also be configured to apply product-specific tax rules where applicable.


Sales tax collection can be automated using tax calculation software that integrates with e-commerce, accounting, or POS systems. These tools can help calculate applicable sales tax in real time based on transaction details and jurisdiction rules. Avalara AvaTax seamlessly integrates with the business systems you already use to deliver sales and use tax calculations in real time.


Tax-exempt goods


Some goods are exempt from Connecticut sales tax under state law. Common exemptions include most unprepared grocery food items, prescription medications, and certain qualifying medical devices and supplies as defined by Connecticut law. Taxability can vary based on product classification, so businesses should consult current Connecticut Department of Revenue Services guidance for specific determinations.


We recommend businesses review the laws and rules put forth by the Department of Revenue Services to stay up to date on which goods are taxable and which are exempt, and under what conditions.

Tax-exempt customers

Some customers are exempt from paying sales tax under Connecticut law. Examples include government agencies, some nonprofit organizations, and merchants purchasing goods for resale.


Sellers are required to collect a valid exemption or resale certificate from buyers to validate each exempt transaction.


Misplacing a sales tax exemption/resale certificate


Connecticut sales tax exemption and resale certificates are worth far more than the paper they’re written on. If you’re audited and cannot validate an exempt transaction, the Department of Revenue Services may hold you responsible for the uncollected sales tax. In some cases, late fees and interest will be applied and can result in large, unexpected bills.


Sales tax holidays


Sales tax holidays exempt specific products from sales and use tax for a limited period, usually a weekend or a week. Approximately 20 states offer sales tax holidays every year.


For 2026, Connecticut has scheduled its Sales Tax-Free Week starting on Sunday, August 16 and ending on Saturday, August 22. Eligible items include:

Filing and remittance

You’re registered with the Department of Revenue Services and you’ve begun collecting sales tax. Remember, those tax dollars don’t belong to you. As an agent of the state of Connecticut, your role is that of intermediary to transfer tax dollars from consumers to the tax authorities.


How to file


Once you’ve collected sales tax, you’re required to remit it to the Department of Revenue Services by a certain date. The DRS will then distribute it appropriately.


Filing a Connecticut sales tax return is a two-step process comprised of submitting the required sales data (filing a return) and remitting the collected tax dollars (if any) to the DRS. The filing process forces you to detail your total sales in the state, the amount of sales tax collected, and the location of each sale.


Sales and use tax returns must be filed online through the Connecticut Department of Revenue Services (DRS) myconneCT online center.


Filing frequency


The Department of Revenue Services will assign you a filing frequency. Typically, this is determined by the size or sales volume of your business. State governments generally ask larger businesses to file more frequently. See the filing due dates section for more information.


Connecticut sales tax returns and payments must be remitted at the same time; both have the same due date.


Online filing


You may file directly with the DRS by visiting their site and entering your transaction data manually. This is a free service, but preparing Connecticut sales tax returns can be time-consuming — especially for larger sellers.


Using a third party to file returns


To save time and avoid costly errors, many businesses outsource their sales and use tax filing to an accountant, bookkeeper, or sales tax automation software like AvaTax. This is a normal business practice that can save business owners time and help them steer clear of costly mistakes due to inexperience and a lack of deep knowledge about Connecticut sales tax code.


Filing when there are no sales


Once you have a Connecticut seller’s permit, you’re required to file returns at the completion of each assigned collection period regardless of whether any sales tax was collected. When no sales tax was collected, you must file a “zero return.”


Failure to submit a zero return can result in penalties and interest charges.


Closing a business


The DRS requires all businesses to “close their books” by filing a final sales tax return. This also holds true for business owners selling or otherwise transferring ownership of their business.


Timely filing discount


Many states encourage the timely or early filing of sales and use tax returns with a timely filing discount.


Connecticut does not offer sales tax filers a timely filing discount.

Filing due dates

It’s important to know the due dates associated with the filing frequency assigned to your business by the Department of Revenue Services. This way you’ll be prepared and can plan accordingly. Failure to file by the assigned date can lead to late fines and interest charges.


The DRS requires all sales tax filing to be completed by the last day of the month following the tax period. Below, we’ve grouped Connecticut sales tax filing due dates by filing frequency for your convenience. Due dates falling on a weekend or holiday are adjusted to the following business day.

Connecticut 2026 monthly filing due dates

Reporting period

Filing deadline

January

March 2, 2026

February

March 31, 2026

March

April 30, 2026

April

June 1, 2026

May

June 30, 2026

June

July 31, 2026

July

August 31, 2026

August

September 30, 2026

September

November 2, 2026

October

November 30, 2026

November

December 31, 2026

December

February 1, 2027

 
Connecticut 2026 quarterly filing due dates

Reporting period

Filing deadline

Q1 (January 1–March 31)

April 30, 2026

Q2 (April 1–June 30)

July 31, 2026

Q3 (July 1–September 30)

November 2, 2026

Q4 (October 1–December 31)

February 1, 2027

 
Connecticut 2026 annual filing due date

Reporting period

Filing deadline

January 1–December 31

February 1, 2027

 
Late filing

Filing a Connecticut sales tax return late may result in a late filing penalty as well as interest on any outstanding tax due. For more information, refer to our section on penalties and interest.


In the event a Connecticut sales tax filing deadline was missed due to circumstances beyond your control (e.g., weather, accident), the DRS may grant you an extension. However, you may be asked to provide evidence supporting your claim.

Penalties and interest

Hopefully you don’t need to worry about this section because you’re filing and remitting Connecticut sales tax on time and without incident. However, in the real world, mistakes happen.


If you miss a sales tax filing deadline, follow the saying, “better late than never,” and file your return as soon as possible. Failure to file returns and remit collected tax on time may result in penalties and interest charges, and the longer you wait to file, the greater the penalty and the greater the interest.


If you are acquiring a business, it is strongly recommended that you review the seller’s Connecticut tax compliance status and confirm that all required sales and use tax accounts are properly addressed with the Connecticut Department of Revenue Services (DRS).

Shipping and handling

If you’re collecting sales tax from Connecticut residents, you’ll need to consider how to handle taxes on shipping and handling charges.


Taxable and exempt shipping charges


Connecticut sales tax may apply to charges for shipping, handling, delivery, freight, and postage. Generally, if the sale is taxable, these charges are taxable even if separately stated; if the sale is tax-exempt, the shipping and handling charges are most likely exempt as well.


There are exceptions to almost every rule with sales tax, and the same is true for shipping and handling charges. Specific questions on shipping in Connecticut and sales tax should be taken directly to a tax professional familiar with Connecticut tax laws.


For the latest bulletins and information, see the Connecticut Department of Revenue Services portal.

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