Missouri charges 4.225% state sales tax on all vehicle purchases, plus local sales tax that ranges from 0% to 5.975% depending on your county
Your total sales tax on a car in Missouri is the state rate plus your local rate combined. The state portion is always 4.225%. Your county or city may add additional tax, which means the total you pay ranges from 4.225% to 10.2% depending on where you live. A $20,000 car in St. Louis County costs different tax than the same car in rural Pike County.
Sales tax applies to the purchase price of the vehicle itself, not to trade-in value. If you trade in a car worth $5,000 toward a $20,000 purchase, you pay tax only on the $15,000 difference. This is called the trade-in credit and is one of the few ways to reduce your taxable amount.
Key Takeaways
- Missouri's state sales tax on cars is 4.225%, and your county adds between 0% and 5.975% on top of that.
- You pay sales tax on the net purchase price after subtracting any trade-in value, not on the full sticker price.
- The tax is collected by the dealer at the time of sale and sent to the state and local tax authorities.
- Private party sales are taxed the same way as dealer sales, and you owe the tax even if you buy from someone you know.
How to find your local sales tax rate
Your local rate depends on which county and city you live in. Missouri has 114 counties, and each one sets its own local sales tax. Some counties have no local tax at all; others add nearly 6%. The easiest way to find your exact rate is to enter your zip code into the Missouri Department of Revenue's sales tax lookup tool on their website, or call your county assessor's office.
If you are buying the car in one county but registering it in another, the tax rate that applies is the one where the sale happens, not where you live. This matters if you buy from a dealer in a neighboring county with a lower rate.
What the sales tax actually covers
Sales tax applies to the vehicle itself and any parts or accessories the dealer installs before you take possession. If you buy floor mats, a roof rack, or an extended warranty at the time of purchase, those are typically taxed as part of the sale. However, if you buy accessories after you leave the lot, those are taxed separately under regular retail sales tax rules.
Documentation fees, dealer prep charges, and registration fees are separate from sales tax. These are not taxable, but they are added to your total bill. Sales tax does not apply to financing charges or interest.
Trade-in credits and how they reduce your tax
If you trade in a vehicle, the dealer subtracts its value from the purchase price before calculating tax. This is the main way to lower your taxable amount. A $25,000 car with a $5,000 trade-in means you pay tax on $20,000, not $25,000. The trade-in value must be documented on your bill of sale.
The trade-in credit applies only if you are trading a vehicle to the same dealer you are buying from. If you sell your old car privately and use the cash to buy a new one, you pay full tax on the new car's price.
Private party sales and tax responsibility
When you buy a car from another person rather than a dealer, you still owe Missouri sales tax. You do not pay it at the time of sale; instead, you pay it when you register the vehicle with the Missouri Department of Revenue. The registration office calculates tax based on the purchase price you report on the bill of sale.
This means you need a written bill of sale showing the price you paid. If you do not have one, the state may assess tax based on the vehicle's book value instead, which could be higher than what you actually paid. Always get a signed bill of sale from a private seller before handing over money.
When sales tax does not apply
Sales tax does not apply to vehicles purchased by certain nonprofits, government agencies, or organizations with a tax-exempt status. If your organization qualifies, you will need to provide documentation of your exempt status to the dealer before the sale. The dealer cannot simply take your word for it.
Vehicles used for specific commercial purposes may may have access to for a sales tax exemption in some cases, but this is rare and requires advance approval from the Missouri Department of Revenue. Do not assume your vehicle qualifies; contact the department before you buy.
Frequently Asked Questions
Do I pay sales tax on a used car the same way as a new car?
Yes. The sales tax rate and rules are identical whether you buy new or used. The only difference is the purchase price, which is typically lower for used vehicles. Trade-in credits work the same way for both.
What if I buy a car in Missouri but register it in another state?
You pay Missouri sales tax at the time of purchase because that is where the sale occurs. You do not owe tax to the other state unless you move there and register the vehicle after it is already registered in Missouri. Check with the other state's motor vehicle office about their rules.
Can I avoid sales tax by buying out of state?
No. If you are a Missouri resident, you owe Missouri sales tax on a vehicle you buy anywhere, even if you buy it in a state with no sales tax. You pay the tax when you register the vehicle in Missouri. The only exception is if you buy the car in another state and register it there before moving to Missouri.
Does sales tax apply to vehicle financing or loan interest?
No. Sales tax applies only to the purchase price of the vehicle itself. Interest, loan fees, and financing charges are not taxed. However, they are added to your total amount owed to the lender.
What happens if I disagree with the purchase price the dealer used to calculate tax?
You can dispute the taxable value with the Missouri Department of Revenue if you believe the dealer overvalued the vehicle. You will need documentation showing what you actually paid, such as your bill of sale or purchase agreement. Contact the department's taxpayer assistance line to file a dispute.