What you sign, what happens to your plates, what the buyer pays, and how much a trade-in saves in sales tax in Illinois. Last checked 2026-10-30.
Short answer: to sell a car privately in Illinois, you sign the title over to the buyer in its assignment section and write in the mileage. Take your plates and stickers off: in Illinois they don't go with the car. You can move them to another car you own ($25) or return them to the Secretary of State. The buyer has 20 days to apply for a new title ($165) and pays a flat private-party tax that depends on the car's age or price, not the 6.25% a dealer charges. If you trade in at a dealer instead, Illinois taxes the price of the car you buy minus your trade-in, with no cap since 2022: on a $10,000 trade-in that's $625 less state sales tax.
| Step | What to do |
|---|---|
| Sign the title over | The seller fills in "an assignment and warranty of title" in the space on the certificate of title and delivers it to the buyer (or mails it to the Secretary of State) (625 ILCS 5/3-112). Don't hand over a title signed but otherwise blank. |
| Write in the mileage | Federal law requires a written odometer disclosure when ownership changes (see below). Write the actual number from the odometer the day you sell. |
| Clear any loan first | If you still owe on the car, the lender's lien has to be released before the title can move to the buyer. Pay it off, or sell through a dealer that pays it off for you. |
| Take your plates off | When you sell, the registration on that car ends, with no refund. You remove the plates and stickers and either return them to the Secretary of State or transfer them to another car you own (625 ILCS 5/3-501). The transfer fee is $25 (625 ILCS 5/3-821). |
| Keep proof of the sale | Keep a copy of the signed title and a bill of sale with the buyer's name, date, price and mileage. It's your record of when the car stopped being yours. |
| Item | Amount |
|---|---|
| Certificate of title | $165 (625 ILCS 5/3-821) |
| Deadline to apply for the title | Within 20 days of getting the car and the signed title (625 ILCS 5/3-112) |
| Private-party tax (Form RUT-50) | A flat amount by the car's age, or by price at $15,000 and up (table below). Due within 30 days, paid to the Secretary of State with the title application (Illinois Department of Revenue) |
| Chicago and Cook County | An extra local private-party tax for buyers who live there, also by the car's age (IDOR RUT-6 guide) |
| Plates | Their own: a new registration, or $25 to move plates they already have |
When the price is under $15,000, the tax depends only on the car's age (the year the buyer titles it minus the model year):
| Car's age | Tax |
|---|---|
| 1 year or less | $465 |
| 2 years | $365 |
| 3 years | $290 |
| 4 years | $240 |
| 5 years | $190 |
| 6 years | $165 |
| 7 years | $155 |
| 8 years | $140 |
| 9 years | $125 |
| 10 years | $115 |
| 11 years or more | $100 |
At $15,000 and up, it depends on the price:
| Price | Tax |
|---|---|
| $15,000 to $19,999.99 | $850 |
| $20,000 to $24,999.99 | $1,100 |
| $25,000 to $29,999.99 | $1,350 |
| $30,000 to $49,999.99 | $1,600 |
| $50,000 to $99,999.99 | $2,600 |
| $100,000 to $999,999.99 | $5,100 |
| $1,000,000 and up | $10,100 |
Source: IDOR Form RUT-50 instructions (revised April 2026).
Why this matters to you as the seller: a private buyer in Illinois usually pays far less tax than a dealer customer. On an 8-year-old car sold for $10,000, a private buyer pays $140 in state tax; the same car bought from a dealer is taxed at 6.25%, $625. That gap is part of what makes a private sale worth it in Illinois, on top of the dealer's margin.
Federal law requires a written mileage disclosure when ownership changes. Cars from model year 2011 on stay covered until they're 20 years old; model year 2010 and older are exempt (49 CFR 580.17).
Illinois taxes the selling price minus the trade-in credit when you trade a car in to the dealer you buy from, new or used. From 2020 through 2021 the credit was capped at $10,000; "for sales made on or after January 1, 2022, the $10,000 trade-in credit limit no longer applies" (IDOR Form ST-556 instructions). At the 6.25% state rate:
| Trade-in value | State sales tax saved (new or used) |
|---|---|
| $5,000 | $312 |
| $10,000 | $625 |
| $15,000 | $938 |
| $20,000 | $1,250 |
Local sales tax adds more in many places, so the real saving is often a bit higher. Sell the car yourself and buy from a dealer, and you pay tax on the full price of the next car. That saving is what a private sale has to beat. Trade in or sell it yourself? · Trade-in tax in other states
Who keeps the license plates when you sell a car in Illinois? The seller. When you sell, the registration on that car ends; you take the plates and stickers off and either return them to the Secretary of State or transfer them to another car you own for $25. The buyer gets their own plates.
How long does the buyer have to title a car in Illinois? 20 days after getting the car and the signed title. The title fee is $165, and the private-party tax (Form RUT-50) is due within 30 days, paid to the Secretary of State with the title application.
How much tax does a buyer pay on a private car sale in Illinois? A flat amount, not a percentage, when the price is under $15,000: from $100 for a car 11 or more years old to $465 for a car a year old or newer. At $15,000 and up it goes by price, starting at $850. Buyers in Chicago and Cook County pay an extra local amount.
Does a trade-in lower the sales tax in Illinois? Yes, new or used, with no cap since January 1, 2022. Illinois taxes the price minus your trade-in when you trade it to the dealer you buy from. At the 6.25% state rate, that's $625 less tax on a $10,000 trade-in, and local tax can add a little more.
Is there still a $10,000 cap on the Illinois trade-in tax credit? No. The cap applied only to sales in 2020 and 2021. It ended January 1, 2022.
General information from Illinois and federal sources, not legal or tax advice. Check with the Illinois Secretary of State before you sell. How we estimate your trade-in value · Selling in Michigan · Selling in Ohio · Selling in Indiana · Selling in Wisconsin
How we calculate it · Trade-in tax by state · What dealers make · Trade in or sell? · What dealers check · Owe more than it's worth? · When to sell · Selling a car by state · Stop calls & texts