What a Car 603 Credit Is and Who Can Use It

A Car 603 credit is a New Hampshire state tax credit for people who buy or lease a new vehicle that meets certain fuel-efficiency or emissions standards. The state offers this credit to reduce the tax burden on buyers of may have access to vehicles, typically those that are electric, hybrid, or meet strict emissions requirements. You claim the credit on your New Hampshire state tax return, not when you buy the car.

The credit is not a rebate from the dealership or manufacturer — it reduces the amount of New Hampshire tax you owe when you file your return. If you buy a may have access to vehicle in New Hampshire or are a New Hampshire resident who buys one elsewhere, you may be able to claim it. The vehicle must be new (not used) and registered in New Hampshire to count.

The credit amount and which vehicles may have access to change year to year based on state law and available funding. You will need to check the current tax year's rules before you buy, because not all new vehicles may have access to, and the program may have reached its annual cap.

Key Takeaways

  • A Car 603 credit is claimed on your New Hampshire state tax return and reduces the tax you owe, not the price you pay at the dealership.
  • Only new vehicles that meet New Hampshire's fuel-efficiency or emissions standards may have access to, and the list of approved models changes each year.
  • You must register the vehicle in New Hampshire and own or lease it for the full tax year to claim the credit.
  • The New Hampshire Department of Revenue Administration publishes the current list of may have access to vehicles and credit amounts before each tax year begins.
  • If the annual credit cap is reached, later buyers in that year may not be able to claim the credit even if their vehicle qualifies.

Check If Your Vehicle Qualifies Before You Buy

The New Hampshire Department of Revenue Administration maintains a list of vehicles that meet the Car 603 standards for the current tax year. Visit the department's website and look for the "Car 603 Credit" page or search for "New Hampshire vehicle tax credit." The list shows which makes and models may have access to and the credit amount for each.

Qualification is based on the model year of the vehicle, not the year you buy it. A 2024 model-year vehicle bought in 2025 still counts as a 2024 model for credit purposes. Check the list for your specific model year and trim level, because sometimes only certain versions of a vehicle may have access to — for example, a hybrid version but not the gas-only version.

If your vehicle is not on the list, it does not may have access to, and you will not be able to claim the credit. Dealerships do not always know which vehicles may have access to, so do not rely on their answer. Check the state list yourself before you commit to a purchase.

Gather Your Documents and Vehicle Information

To claim the credit when you file your tax return, you will need your vehicle's Vehicle Identification Number (VIN), the date you took ownership or began the lease, and proof that the vehicle is registered in New Hampshire. You will also need your New Hampshire tax return and the form or schedule the state uses for the Car 603 credit in that tax year.

Keep your purchase agreement or lease agreement and your vehicle registration certificate. You do not send these documents with your return, but you must have them if the state asks you to prove you owned the vehicle during the tax year. If you bought the vehicle partway through the year, note the exact date — you may only claim a partial credit if you did not own it for the full 12 months.

If you leased the vehicle, the lease agreement must show that you are the lessee and that the vehicle qualifies. Some leases do not count toward the credit, so check your lease terms or contact the leasing company to confirm the vehicle is may be able to access.

File Your Tax Return and Claim the Credit

When you file your New Hampshire state tax return for the year you bought or leased the vehicle, you will report the Car 603 credit on the appropriate form or schedule. The New Hampshire Department of Revenue Administration publishes the tax forms and instructions each year. Look for a schedule or line item labeled "Car 603 Credit" or "Vehicle Tax Credit."

Enter your VIN, the date you took ownership, and the credit amount from the state's list of may have access to vehicles. If you are using tax software, the program may have a field for this credit — search for "Car 603" or "vehicle credit" in the software's index. If you are filing by hand, follow the instructions on the form exactly, because errors can delay your refund or trigger an audit.

File your return by the state important date (usually April 15 for the prior tax year). The credit reduces your tax liability dollar-for-dollar, so if you owe $500 in New Hampshire tax and claim a $1,000 credit, you will receive a $500 refund instead.

What Happens If the Annual Credit Cap Is Reached

New Hampshire sets an annual limit on the total amount of Car 603 credits the state will issue. Once that cap is reached, no more credits are issued for that tax year, even if your vehicle qualifies. If you buy a may have access to vehicle late in the year and the cap has already been hit, you will not be able to claim the credit.

The state does not notify buyers when the cap is approaching — you have to check the Department of Revenue Administration website or call them to ask whether credits are still being issued. If you are buying a vehicle late in the year and the credit matters to your decision, contact the department before you buy to confirm the cap has not been reached.

If you miss the cap in one year, you cannot carry the unused credit forward to the next year. The credit is only available for the tax year in which you owned the vehicle.

Leasing vs. Buying: How the Credit Works for Each

If you buy a may have access to vehicle, you claim the full credit on your tax return for the year you took ownership. You own the vehicle for the full tax year, so you claim the credit once and you are done.

If you lease a may have access to vehicle, you can claim the credit for each tax year you hold the lease, as long as the vehicle still qualifies that year. A three-year lease means you can claim the credit for up to three tax years (the year you started the lease, the second year, and the third year). However, the may have access to vehicle list changes each year, so your leased vehicle might not may have access to in year two or three even if it may have access to in year one.

Some leasing companies handle the credit differently — a few may claim it themselves and pass the benefit to you as a lower payment. Ask your leasing company whether they claim the Car 603 credit or whether you claim it on your tax return. Do not assume you can claim it if the company already has.

Common Mistakes to Avoid

The most common mistake is buying a vehicle you think qualifies without checking the state's official list first. Dealerships sometimes tell buyers a vehicle qualifies when it does not, or the list has changed since the dealer last checked. Always verify on the Department of Revenue Administration website before you buy.

Another mistake is claiming the credit if you did not own the vehicle for the full tax year. If you bought the vehicle on November 1, you may only claim a partial credit (roughly two months' worth). Read the state's instructions carefully to see how partial-year ownership is calculated.

Do not forget to include your VIN on the form. The state uses it to verify the vehicle qualifies. A missing or incorrect VIN can cause the credit to be denied, and you will have to file an amended return to correct it.

Finally, do not assume the credit carries over to the next year if you do not claim it. Tax credits have important date, and missing the important date to file your return means missing the important date to claim the credit for that year.

Frequently Asked Questions

Can I claim the Car 603 credit if I bought the vehicle out of state?

Yes, if you are a New Hampshire resident and the vehicle is registered in New Hampshire. The credit is based on your residency and the vehicle's registration, not where you bought it. You will still need to check the state's may have access to vehicle list to confirm your model qualifies.

What if I sell the vehicle before the end of the tax year?

You can still claim the credit for the year you owned it, even if you sold it partway through. You claim the credit based on the months you held the vehicle. Check the state's instructions for how to calculate a partial-year credit if you sold it before December 31.

Does the Car 603 credit work with federal tax credits for electric vehicles?

Yes. The state credit and the federal credit are separate, and you can claim both. However, the federal credit has its own income limits and vehicle price caps, so not all vehicles that may have access to for the state credit also may have access to for the federal one. Check both the New Hampshire Department of Revenue Administration and the IRS website to see what you are may have access to to.

What if the state denies my credit claim?

The state will send you a notice explaining why. Common reasons are a missing or incorrect VIN, the vehicle not being on the may have access to list, or the annual cap being reached. You can file an amended return to correct errors, or you can contact the Department of Revenue Administration to ask whether the denial can be reviewed.

Can I transfer the credit to someone else if I do not use it?

No. The Car 603 credit is personal to the vehicle owner or lessee and cannot be transferred. If you do not claim it on your tax return for the year you owned the vehicle, you lose it.