Illinois Trailer Bill of Sale: Use Tax, Registration, and RUT-50

An Illinois trailer bill of sale is the written record of a private trailer sale that the buyer uses to apply for a title, that the Department of Revenue uses to set the private-party use tax, and that fixes the date the seller stops being responsible for the trailer. Illinois does not require it to be notarized, and there is no single mandatory state form, but the document has to carry enough detail to support the title application and the tax filing that follow.

What to Put on the Bill of Sale

Because Illinois does not prescribe a form for private trailer sales, the content is what matters. A workable bill of sale includes:

The Vehicle Identification Number or serial number, usually stamped on the frame or tongue. This is the identifier the Secretary of State uses to track the trailer.
Year, make, and model. The title application requires a description of the vehicle including these details.¹
Empty weight. Weight determines the plate category, so you need this figure before you walk into a Secretary of State facility.
The actual purchase price. Understating the price to reduce tax is fraud, and the Department of Revenue can assess tax on fair market value instead.
Full legal names and addresses of both buyer and seller.
Date of sale. This anchors both the tax filing and the transfer of liability.
Signatures of both parties.

If the trailer has an odometer (uncommon, but some larger enclosed trailers do), the seller must disclose the current reading and whether it reflects actual mileage.¹

Keep a signed copy. If a ticket or towing bill turns up later tied to the trailer, the dated bill of sale is what shows it was no longer yours.

What the Buyer Will Pay

Three separate charges hit the buyer at the counter: the title fee, the registration fee, and the private-party use tax reported on Form RUT-50. The title fee is $165. The other two vary.

Private-Party Use Tax on Trailers Under $15,000

Below a $15,000 purchase price or fair market value, the tax is set by the trailer’s model year, not its price. For 2026:²

1 year old or newer (2025+): $465
2 years old (2024): $365
3 years old (2023): $290
4 years old (2022): $240
5 years old (2021): $190
6 years old (2020): $165
7 years old (2019): $155
8 years old (2018): $140
9 years old (2017): $125
10 years old (2016): $115
11 years or older (2015 and earlier): $100

A twenty-year-old utility trailer bought for $500 still owes $100 in use tax. There is no low-price exemption.

Private-Party Use Tax on Trailers $15,000 and Up

At $15,000 the tax switches to purchase-price brackets:²

$15,000 to $19,999: $850
$20,000 to $24,999: $1,100
$25,000 to $29,999: $1,350
$30,000 to $49,999: $1,600
$50,000 to $99,999: $2,600
$100,000 to $999,999: $5,100

Reduced-Rate and Exempt Transfers

Transfers between immediate family (spouse, parent, sibling, or child, including adopted children) are taxed at a flat $15. Step-relatives, in-laws, and grandparents do not qualify. Estate gifts to a surviving spouse are fully exempt; estate gifts to other beneficiaries are $15. Tax-exempt organizations pay nothing.²

Registration Fees for Standard Trailers

A trailer of 3,000 pounds or less uses a TA plate. The annual registration fee is $36, prorated by quarter within the state’s May-through-April registration year. Combined with the $165 title fee, a new title-and-plate transaction runs:³

May 1 through July 31: $201
August 1 through October 31: $192
November 1 through January 31: $183
February 1 through April 30: $174

Registration Fees for Recreational Trailers

Boat trailers, campers, and similar units use RT plates, with annual registration set by weight:⁴

3,000 lbs or less: $18
3,001 to 8,000 lbs: $30
8,001 to 10,000 lbs: $38
10,001 lbs and over: $50

Add the $165 title fee to whichever registration figure applies. Heavier commercial trailers may fall into different plate categories at higher fees.

Getting the RUT-50

Form RUT-50 is generally handed out when you title and register the trailer at a Secretary of State facility or a currency exchange. Each copy has a unique transaction number, so do not photocopy blanks. The form is also stocked at Illinois Department of Transportation and Department of Natural Resources offices.⁵

Completing the Transfer

The sequence is short but unforgiving of missing pieces.

Get the signed title from the seller at the time of sale. Illinois law requires the seller to sign the assignment section on the back of the certificate of title and deliver it to the buyer then. Do not accept a promise to mail it later; that is the single most common source of trouble in private trailer sales.
Fill out the bill of sale. Both parties sign. Keep a copy.
Complete Form RUT-50 with the price, trailer description, and both parties’ information.
Bring the signed title, bill of sale, completed RUT-50, and payment for the title fee, registration fee, and use tax to a Secretary of State facility, or mail the package to the Secretary of State in Springfield with a check or money order.

Walk-in visits produce same-day plates. Mail-in applications take several weeks.

What the Seller Has to Do

Two obligations protect the seller after the trailer leaves the driveway.

First, sign the assignment section on the back of the title and hand the title to the buyer at the time of sale. Holding onto the title after taking payment creates legal risk for both sides.

Second, complete a Seller’s Report of Sale and mail it to the Secretary of State’s Vehicle Services Department in Springfield. This is what releases you from responsibility for the trailer going forward.⁶ Skipping this step means the state’s records still show you as the owner if the buyer never titles the trailer and it later gets abandoned, ticketed, or wrecked. The form is short and free. Mail it the day you hand over the title.

Missing Title

Trailers that have sat unused for years often have lost titles. If the current titled owner has misplaced the paperwork, they can apply for a duplicate using Form VSD 190 for a $50 fee, in person or by mail.⁷

There is a built-in delay: no duplicate within 15 days of an original title’s issuance, or within 30 days of a previous duplicate. If a lien is on record, the duplicate goes to the lienholder rather than the owner.⁷

As a buyer, do not close on a trailer where the seller cannot produce a title. Have them get the duplicate first. A bill of sale alone leaves you with no guaranteed path to registration, and the Secretary of State can reject the application if the chain of ownership is not documented.

Existing Lien on the Trailer

If a lienholder is named on the title, the seller has to pay the loan off and obtain a lien satisfaction letter on the lender’s letterhead before the title can be transferred cleanly. Without that letter, the Secretary of State will not process the transfer into the buyer’s name.⁸

The practical fix is to meet at the lender’s office so the payoff and title release happen at the same time. Never hand cash to a seller who promises to pay off the lien afterward.

Homemade and Custom-Built Trailers

A trailer built from parts, never issued a manufacturer’s ownership document, and with no prior registration history is classified as homemade under Illinois administrative rules, and the titling process is different. The owner submits a signed affirmation that the trailer is homemade, a statement of construction listing materials, four photographs (both sides, front, and rear), and the title and registration fees. After paperwork approval, the Secretary of State Department of Police inspects the trailer for safety and stolen parts, and trailers over 5,001 pounds also require an Illinois Department of Transportation inspection. Once it passes, the police assign and attach a VIN that becomes part of the permanent record.⁹

1
Illinois General Assembly. 625 ILCS 5/3-104
2
Illinois Department of Revenue. RUT-5, Private Party Vehicle Use Tax Chart for 2026
3
Illinois Secretary of State. TA Trailer (3,000 Pounds or Less) License Plates
4
Illinois Secretary of State. Basic Fees
5
Illinois Department of Revenue. Obtaining Forms RUT-25, RUT-25-LSE, and RUT-50
6
Illinois Secretary of State. Seller’s Report of Sale
7
Illinois Secretary of State. Duplicate Titles
8
Illinois Secretary of State. Title and Registration Checklist – Loan Paid
9
Legal Information Institute. Illinois Administrative Code Title 92, Section 1010.200