Car Taxes in CT: Rates, Due Dates, and Appeals

Car taxes in Connecticut are billed by your town, not the state, and starting with the October 1, 2024 assessment year every municipality values vehicles the same way: the manufacturer’s suggested retail price (MSRP) is run through a statutory depreciation schedule, assessed at 70% of that depreciated value, and multiplied by the town’s motor vehicle mill rate, which is capped at 32.46 mills.¹

How Your Vehicle’s Value Is Set

Assessors begin with the vehicle’s original MSRP and apply a depreciation percentage based on its age on the October 1 assessment date. If the MSRP cannot be determined, the assessor sets a value in consultation with the Connecticut Association of Assessing Officials.¹

The default schedule reduces the MSRP percentage as the vehicle ages:²

Up to 1 year old: 85% of MSRP
2 years: 80%
3 years: 75%
4 years: 70%
5 years: 65%
6 years: 60%
7 years: 55%
8 years: 50%
9 years: 45%
10 years: 40%
11 years: 35%
12 years: 30%
13 years: 25%
14 years: 20%
15–19 years: 15%
20 years and older: minimum $500 value

Under Public Act 25-2, your town can vote to use a modified schedule that starts at 90% of MSRP for the first year and drops more slowly after that.² Call your town assessor to confirm which table is in effect where you live.

Whichever schedule applies, the depreciated value is then taxed at 70%. A $40,000 MSRP vehicle that is three years old depreciates to $30,000 (75% of MSRP), and is assessed at $21,000 (70% of $30,000). That $21,000 is the figure on your bill.¹

Unregistered and non-running vehicles get taxed too. Since the 2024 assessment year, a car sitting without plates in your driveway is valued the same as any other vehicle.¹

Antique Vehicles

A vehicle that qualifies as antique, rare, or special interest is assessed at a flat $500 no matter what it is worth. To qualify, it must be at least 20 years old, preserved for historical interest, and unmodified from the manufacturer’s specifications. Antique plates are not required, but without them the assessor can ask for documentation.³

Disabled Veterans

Veterans with a service-connected permanent and total disability rating from the U.S. Department of Veterans Affairs qualify for a property tax exemption. It normally applies to the primary residence, but a veteran who does not own a home can apply it to one motor vehicle instead. The veteran must live in Connecticut and file with the town assessor.⁴

Calculating What You Owe

A mill equals one dollar of tax for every $1,000 of assessed value, so the math is assessed value times mill rate, divided by 1,000.⁵ Towns set mill rates annually, and current rates are posted on the OPM website and most town sites.

No municipality or combined taxing district can charge more than 32.46 mills on motor vehicles, even where the real estate rate is higher.¹ Using the $21,000 assessment from above in a town at the cap: $21,000 × 32.46 ÷ 1,000 = $681.66. In a town at 25 mills, the same vehicle owes $525.

When the Bill Is Due

Regular motor vehicle bills are due July 1 and are based on the previous October 1 grand list. You have a grace period of about 30 days, so payment must reach the town by August 1 to avoid interest.⁶

Register a vehicle after October 1 and you’ll get a supplemental bill instead, prorated for the months left in the assessment year. Supplemental billing schedules vary by town; some bill monthly, others at set intervals.⁷ Call your tax collector if you are not sure when yours is coming.

Miss the deadline and interest accrues at 1.5% per month (18% per year), backdated to the original due date.⁷ On a $600 bill, that’s $9 the first month and it keeps compounding. Most towns take payment online, by mail, or in person, though online card and e-check payments usually carry a fee.

If You Sold, Totaled, or Moved the Car

You can get a prorated credit so you only pay for the months you actually had the vehicle registered in that town, but the town will not adjust the bill on its own. You bring documentation to the assessor, and the key document is the plate return receipt from the Connecticut DMV.⁸ If you did not get one when you turned in your plates, request a duplicate from the DMV.

The plate receipt alone is not enough. You also need a second document proving what happened to the car:⁹

Sold or donated: a bill of sale, trade-in agreement, or title transfer record.
Stolen or totaled: a letter from your insurer on their letterhead listing the VIN, the date the title was taken, and a statement that the vehicle was a total loss or not recovered.
Moved out of state: a copy of your out-of-state registration or title from the new state’s DMV.

The deadline is December 31 following the first full assessment year after the event.¹⁰ Sell a vehicle in March 2026 and you have until December 31, 2027 to file. Miss the deadline and you stay on the hook for the full tax.

One trap worth flagging: if you move out of Connecticut without canceling your registration, the car stays on the town’s grand list and the bills keep coming. Cancel your plates through the DMV’s online system or by mail before you leave.⁸

Appealing the Assessment

Think your value is wrong? You can appeal to your town’s Board of Assessment Appeals, which hears motor vehicle appeals in September. Under the MSRP-based system, the board can only consider whether the correct MSRP was used. High mileage, poor condition, and accident damage are not grounds for a reduction.¹¹

MSRP errors do happen, particularly on vehicles with unusual trim levels or factory option packages. If the assessor used the wrong MSRP for your specific build, an appeal is worth the trouble. Watch your town assessor’s website in mid-August; filing windows are short.

Unpaid Taxes and Your Registration

Connecticut law requires the DMV to deny registrations for anyone reported as tax delinquent. You cannot renew your registration or get new plates until the debt clears, and the DMV no longer accepts paper tax releases. Your town’s tax collector clears the hold electronically, which can take a day or two to show up.¹² If a renewal is coming up, pay well before the expiration date.

Deducting the Tax on Your Federal Return

Connecticut’s motor vehicle property tax counts as a deductible state and local tax if you itemize. For the 2025 tax year, the SALT deduction is capped at $40,000 for most filers, or $20,000 if married filing separately. The cap phases down for modified adjusted gross income above $500,000 but cannot fall below $10,000, and the 2026 cap is expected to be adjusted slightly for inflation.¹³ That $40,000 cap covers all state and local taxes combined, so your vehicle tax is competing for room with your Connecticut income tax and any real estate taxes you pay.

1
Connecticut General Assembly. Connecticut General Assembly Office of Legislative Research – Personal Motor Vehicle Property Tax Assessments and Rates
2
State of Connecticut Office of Policy and Management. Motor Vehicle Assessment Changes Effective October 1, 2024
3
Connecticut General Assembly. Assessment Limit on Antique Vehicles
4
State of Connecticut. Governor Lamont Signs Law Establishing Property Tax Exemption for Veterans
5
State of Connecticut Office of Policy and Management. Mill Rates
6
Town of Wilton. Tax Due Dates
7
Bristol, CT – Official Website. Payment Dates
8
Connecticut Department of Motor Vehicles. Cancel Your Registration and Plates
9
City of Norwalk. Office of the Assessor – Motor Vehicle Adjustment Requirements
10
Connecticut General Assembly. An Act Concerning Motor Vehicle Assessments for Property Taxation
11
Town of Glastonbury. Assessment Appeal Information
12
Connecticut Department of Motor Vehicles. Learn How to Comply with Insurance, Tax, and Registration Laws
13
Internal Revenue Service. How to Update Withholding to Account for Tax Law Changes for 2025