Everything a boat buyer needs to know about sales tax, use tax, registration fees, and title fees in Illinois — with real examples.
Buying a boat in Illinois comes with more paperwork than most people expect. Between state sales tax, local tax, registration fees, and title fees, the final number owed to the state can be significantly higher than the sticker price. This guide walks through every step of the calculation in plain English, using the same rules applied by the Illinois Department of Revenue (IDOR) and the Illinois Department of Natural Resources (DNR).
Step 1
Determine the Tax Rate (State + Local)
Every Illinois boat purchase starts with a 6.25% Illinois state sales or use tax. This base rate is set by Illinois law and applies to everyone — whether you buy from a dealer or a neighbor, whether the boat is new or used. (Illinois Compiled Statutes, Watercraft Use Tax Law; Illinois Department of Revenue guidance.)
On top of that, a local tax may apply — but it depends on how and where you bought the boat.
If you bought from an Illinois dealer: If the dealer is located in Illinois, the local tax is based on the dealer’s city. If you bought from an out-of-state dealer, Illinois uses your home address (where the boat will be registered) to determine the local rate. This is called “destination-based sourcing.” Local rates vary widely across Illinois — Chicago’s combined rate is 10.25%, while many smaller jurisdictions come in closer to 7–8%.
If you bought from a private seller: Only the flat 6.25% state use tax applies. There is no local tax on private-party boat sales. You file this yourself using Form RUT-75 (for watercraft bought within Illinois) or Form RUT-25 (for watercraft purchased out of state). (Illinois DOR, RUT-75 and RUT-25 instructions.)
Example A
Dealer sale in Chicago
You buy a boat from a licensed Chicago dealer. Chicago’s local tax rate is 4.00% on top of the 6.25% state rate.
Total tax rate = 6.25% + 4.00% = 10.25%
Example B
Private sale anywhere in Illinois
You buy a boat from your coworker in Naperville. Regardless of Naperville’s local rate, private sales only owe the state portion.
Total tax rate = 6.25% (state only)
Step 2
Determine the Taxable Base (What You’re Actually Taxed On)
The taxable base is the dollar amount you apply the tax rate to. In most cases, it starts as the purchase price — but several factors can change it.
Gifts and inheritances: If you received a boat as a gift or inherited it, the taxable base is the boat’s fair market value — not zero and not the $1 some people put on paper to try to avoid tax. Illinois law requires that tax be paid on FMV for gifts. (Illinois Watercraft Use Tax Law; IDOR Guidance on gifts and inheritance.)
Trade-in credit: If you’re buying from an Illinois dealer and you trade in your old boat, the dealer can subtract the trade-in value from the purchase price before calculating tax — but only if the dealer regularly buys and sells that type of boat. Trade-in credits do not apply to private-party sales. If you’re selling your old boat privately and using the money toward a new one, there’s no deduction. (Illinois DOR on trade-in treatment; RUT-75 instructions.)
Fair market value check: If you bought the boat at an unusually low price (for example, from a relative), the state can tax you on the higher of the purchase price or fair market value. This prevents people from recording a low sale price to reduce tax.
Out-of-state use depreciation: If you bought the boat outside Illinois and used it there for some time before bringing it to Illinois, you may be entitled to a depreciation adjustment. Illinois allows a reduction of roughly 1% per month of documented out-of-state use, capped at 50%. So if you used the boat for 10 months out of state, your taxable base could be reduced by 10%. (35 ILCS 105/3-10; IDOR guidance on depreciation for out-of-state use.)
Example A
Dealer sale with a trade-in
You buy a boat from an Illinois dealer for $50,000 and trade in your old boat, which the dealer values at $10,000. The dealer regularly sells boats like yours.
Taxable base = $50,000 − $10,000 = $40,000
Example B
Boat purchased out of state and used there for 4 months
You bought a boat in Florida for $100,000 and used it there for 4 months (about 120 days) before bringing it to Illinois.
Depreciation = 4 months × 1% = 4% → $100,000 × 4% = $4,000 reduction
Taxable base = $100,000 − $4,000 = $96,000
Step 3
Calculate the Tax Owed
Once you have the taxable base and the total tax rate, the math is straightforward: multiply one by the other. The result breaks down into state tax and local tax.
Tax credit for taxes already paid: If you paid sales or use tax on this boat in another state, Illinois will credit you for that amount — but only up to the Illinois tax due. You don’t get a refund if the other state’s rate was higher. (Illinois DOR credit for prior taxes paid.)
“If you paid $500 in tax to Wisconsin, and your Illinois tax comes to $800, you only owe $300 more to Illinois.”
Example A
Dealer sale in Springfield (Sangamon County)
Taxable base: $70,000. Combined rate: 6.25% state + 3.00% local = 9.25%.
Total tax = $70,000 × 9.25% = $6,475
State portion: $70,000 × 6.25% = $4,375 | Local portion: $70,000 × 3.00% = $2,100
Example B
Out-of-state purchase with a prior tax credit
Taxable base: $96,000. Rate: 6.25% state + 1.00% local = 7.25%.
Illinois tax = $96,000 × 7.25% = $6,960
You paid $1,000 in tax to Florida. Illinois credits you that amount.
Tax owed to Illinois = $6,960 − $1,000 = $5,960
Step 4
Calculate the Registration Fee
Separate from tax, every boat in Illinois must be registered with the Illinois DNR. The registration fee is based on the length of the boat and is set by state law. These rates were updated effective 2026. (Illinois DNR, Boat Registration Act.)
| Boat Length | Class | Registration Fee |
|---|---|---|
| Under 16 feet | Class 1 | $28.00 |
| 16 to 25 feet | Class 2 | $60.00 |
| 26 to 39 feet | Class 3 | $160.00 |
| 40 to 64 feet | Class 4 | $210.00 |
| 65 feet and over | Class 5 | $210.00 |
Example A
20-foot boat (Class 2)
A 20-foot bowrider falls in the 16–25 foot range.
Registration fee = $60.00
Example B
32-foot cabin cruiser (Class 3)
A 32-foot cruiser falls in the 26–39 foot range.
Registration fee = $160.00
Step 5
Calculate the Title Fee
As of 2018, Illinois requires a title for boats that are 22 feet or longer. Shorter boats only need registration numbers — no title is required. If your boat is 22 feet or more, a one-time title fee of $10.00 applies. (Illinois DNR, title requirement update effective 2018.)
This is a simple threshold: if the boat is 22 feet or longer, add $10. If it’s shorter, title fee is $0.
Example A
18-foot fishing boat
At 18 feet, this boat is under the 22-foot threshold. No title required. Title fee = $0.
Example B
25-foot pontoon boat
At 25 feet, this boat meets the title requirement. Title fee = $10.00.
Step 6
Any Additional Fees
In some situations, you may need a duplicate title or a duplicate registration decal. These are flat fees set by the Illinois DNR. (Illinois DNR fee schedule.)
A duplicate title costs $7.00. A duplicate decal also costs $7.00. These only apply if you’ve lost or damaged the originals and need replacements. For most new boat purchases, these fees won’t come up.
Example A
New purchase with no lost documents
You’re registering a newly purchased boat for the first time. You don’t need duplicates.
Additional fees = $0.00
Example B
Replacing a lost title and lost decal
You bought a used boat and the previous owner lost both the title and the decal.
Duplicate title fee: $7.00 + Duplicate decal fee: $7.00 = $14.00
Step 7
Add It All Up — Your Total Due
The total amount owed to the state is the sum of all taxes and fees. There’s no mystery here — it’s just addition once each component has been calculated.
Total Due = Tax owed + Registration fee + Title fee (if applicable) + Duplicate fees (if applicable)
Example A
New 25-foot boat from a Chicago dealer
Purchase price: $60,000 | Tax rate: 10.25% (Chicago dealer sale)
Tax: $60,000 × 10.25% = $6,150
Registration fee (Class 2, 16–25 ft): $60.00
Title fee (25 ft ≥ 22 ft): $10.00
No duplicates needed: $0
Total Due = $6,150 + $60 + $10 = $6,220
Example B
Gifted 22-foot sailboat in Rockford
Fair market value: $15,000 | Tax rate: 8.25% (6.25% state + 2.00% Winnebago County)
Tax: $15,000 × 8.25% = $1,237.50
Registration fee (Class 2, 22 ft): $60.00
Title fee (22 ft = exactly 22 ft, title required): $10.00
Total Due = $1,237.50 + $60 + $10 = $1,307.50
Step 8 (Optional)
Financing Estimate
If you’re financing the boat, you may want to know your monthly payment. Illinois taxes are due at the time of purchase regardless of how you pay — financing doesn’t delay or reduce tax. But an estimated monthly payment can help you plan your budget.
The calculator uses the standard loan amortization formula. You provide the loan amount (either the purchase price plus total fees, or a custom amount), the interest rate, and the loan term in months. The formula divides the principal across equal monthly payments so that each payment covers a portion of interest and a portion of principal.
The total interest you pay over the life of the loan equals the total of all payments minus the original principal. And the total loan cost is simply the principal plus all that interest.
Example A
$50,000 loan at 6% over 60 months
Monthly rate: 6% ÷ 12 = 0.50% per month
Monthly payment ≈ $966.64
Total paid = $966.64 × 60 = $57,998 | Total interest = $7,998
Example B
$20,000 loan at 7.5% over 84 months (7 years)
Monthly rate: 7.5% ÷ 12 = 0.625% per month
Monthly payment ≈ $307.50
Total paid = $307.50 × 84 = $25,830 | Total interest ≈ $5,830
Sources & References
The calculations in this guide are based on the following official Illinois statutes, agency rules, and published guidance. These are the same sources referenced when building the Illinois Boat Tax Calculator.
- Illinois Watercraft Use Tax Law — The primary statute governing use tax on boats purchased outside Illinois or from private sellers. Establishes the 6.25% rate, the fair market value floor, and gift/inheritance valuation rules.
- 35 ILCS 105/3-10 — The Illinois Use Tax Act provision governing depreciation adjustments for property used out of state before being brought into Illinois (1% per month, up to 50%).
- Illinois Department of Revenue — Form RUT-75 Instructions — Official instructions for the Watercraft Use Tax Return filed by individuals registering boats purchased from private sellers or out-of-state dealers. Confirms trade-in disallowance for non-dealer sales.
- Illinois Department of Revenue — Form RUT-25 Instructions — Instructions for the Vehicle/Watercraft Use Tax Return for items purchased outside Illinois. Covers credit for taxes paid to other states.
- Illinois Department of Revenue — Form ST-556 Instructions — The sales tax return filed by licensed Illinois dealers at the point of sale. Covers dealer-collected sales tax and qualified trade-in credits.
- Illinois Department of Revenue — Tax Rate Database / MyTax Illinois — The official tool for looking up local sales and use tax rates by city, county, and ZIP code across Illinois. Used to determine local tax rates for specific locations.
- Illinois DNR — Boat Registration Act and Fee Schedule (2026) — Sets registration fees by boat class and length ($28 for Class 1 through $210 for Class 4/5), title fees ($10), and duplicate fees ($7 each).
- Illinois DNR — Title Requirement Update (2018) — Effective 2018, Illinois requires titles only for watercraft 22 feet and longer. Boats under 22 feet require registration numbers but not a title. The old water usage stamp fee was also repealed at this time.
- Illinois Compiled Statutes — Retailers’ Occupation Tax Act — Establishes that local sales taxes apply to dealer sales and are determined by the location of the sale (or destination for out-of-state dealers).
- Illinois DOR Guidance on Trade-in Credits — Clarifies that trade-in deductions for dealer sales apply only when the dealer regularly buys and sells the same type of watercraft being traded in.
Disclaimer: This guide is for informational and educational purposes only. It is not legal or tax advice. Tax rates, fees, and regulations are subject to change. Always consult the Illinois Department of Revenue, Illinois DNR, or a licensed tax professional for official guidance specific to your situation. Rates current as of 2026.