Idaho boat tax is ordinary sales and use tax, not a separate boat excise. The statewide rate is 6%. On a $40,000 dealer boat with no trade-in, state tax is $2,400. A retailer trade-in of $8,000 cuts the taxable price to $32,000 and the 6% tax to $1,920. A private $15,000 purchase is $900 at registration unless an exemption applies. Some cities or resorts add local sales tax — this page does not assign a county percentage because the Tax Commission’s local list must be checked for your closing place. Parks & Recreation registration fees sit on top of tax; ask that department for the current schedule. The State Tax Commission sets the tax. Parks agents collect ST-109 on first registration or transfer unless a county assessor collects instead.
How much is Idaho boat sales tax and registration?
A dealer collects tax at closing. A private buyer typically pays when the vessel is first registered or transferred, using Form ST-109 unless the county assessor takes the tax. Title and registration fees are Parks & Recreation charges, not a substitute for the 6%.
| Deal (state 6%, no local added) | Taxable base | Idaho tax |
|---|---|---|
| Dealer $40,000, no trade-in | $40,000 | $2,400 |
| Dealer $40,000, $8,000 retailer trade-in | $32,000 | $1,920 |
| Dealer $40,000 with $2,000 manufacturer rebate | $40,000 (rebate stays in) | $2,400 |
| Private $15,000 | $15,000 | $900 |
| Qualifying nonresident ST-104NR | exempt | $0 |
Example: Dealer purchase, $40,000, no trade-in
Scenario: Idaho resident buys a new boat from an Idaho dealer for $40,000. No trade-in. No local sales tax confirmed for this closing. Parks registration will be paid at the agent — amount confirmed with Parks, not on this page.
The $2,400 is the state tax line. Do not treat it as a title fee.
Example: Private purchase, $15,000, paid at registration
Scenario: You buy a used boat from a neighbor for $15,000. You register it in Idaho. No exemption applies.
Private sales are not automatically tax-free in Idaho. The $900 is use or sales tax collected with ST-109, not a casual-sale holiday.
- Idaho State Tax Commission, Sales of Boats and Trailers by Dealers
- IDAPA 35.01.02.113 (ST-109 boat registration affidavit)
The tax rule: 6% sales and use tax
Idaho taxes boats and trailers under sales and use tax unless an exemption applies. The state rate is 6%. The taxable sales price includes freight to the seller, options, and many fees. It excludes title and registration charges, optional warranties, and finance charges when those items are separately stated. A manufacturer rebate stays in the sales price — it does not shrink the 6% base.
Use tax covers Idaho use of a boat bought without Idaho tax. Nonresidents who qualify on Form ST-104NR can take the boat out immediately, register or title it outside Idaho, and stay within the 90-day / 12-month use limit (counting 16-hour days). That path is $0 Idaho tax when the criteria are met. It does not cover a paddlecraft without a motor bought in Idaho — that purchase stays taxable even for a nonresident.
Accessory labor installed on a new vessel that is 11 feet or longer, or that has a motor, has been exempt since 2019. Parts on that job may still be taxable. Ask the Tax Commission how the dealer should split the invoice.
Example: Manufacturer rebate stays in the tax base
Scenario: Sticker $40,000. The factory mails a $2,000 rebate. No trade-in. Someone tells you tax is 6% of $38,000.
A retailer trade-in is the reduction that actually cuts the base. A factory rebate is not that reduction.
Example: Accessory labor on a new 18-foot outboard
Scenario: New 18-foot boat with a motor. Dealer invoices $1,200 parts and $800 labor to install a GPS and wiring at sale. State rate 6%.
Do not zero the entire accessory invoice. The exemption is labor on a qualifying new vessel, not a blanket accessories holiday.
- STC Sales of Boats and Trailers by Dealers (base, rebates, freight, warranties)
- Idaho Code § 63-3622OO (accessory labor on qualifying new vessels)
Trade-ins, rebates, dealer vs private
A retailer trade-in taken into resale inventory at the time of sale reduces the taxable sales price. Trading a manufactured home does not reduce the boat’s base. Private-party deals do not get an automatic trade-in subtraction on this page — the Tax Commission’s retailer trade-in rule is the one used in the $1,920 example.
Dealer and private channels both pay 6% when taxable. The difference is who collects: the dealer at closing, or you at Parks registration with ST-109. Government, schools, and certain nonprofits use ST-101. Those entity exemptions are not a shortcut for a private buyer.
Example: $8,000 retailer trade-in
Scenario: New boat $40,000. Dealer takes your old boat for $8,000 into inventory at the sale. State 6%. No local listed for this example.
The trade must be a genuine retailer take-in at the time of sale. A side sale to a cousin is not this example.
Example: Same dollars as a private sale — no dealer trade-in math
Scenario: You pay a private seller $32,000 cash for a boat. You still own your old boat. You register the new one in Idaho.
The $1,920 matches the dealer-with-trade example only because $32,000 is the base either way. You did not “get” a trade-in; you simply paid $32,000.
- STC dealer-sales page (retailer trade-in; manufactured-home trade-in does not reduce)
Local sales tax — verify, do not guess a county rate
Idaho’s statewide boat rate is 6%. Some jurisdictions impose local option sales tax on general sales. The local-rate file behind this guide does not publish a named city or county percentage for boats. This page therefore does not assign Ada County, Kootenai County, or any resort city a made-up add-on. Use the Tax Commission’s local rate tools for the delivery or first-use place and the date of the sale.
If the finder shows 0% local, tax is 6% of the base. If it shows a local rate, add that rate to 6% and apply the combined figure to the same taxable sales price. Do not copy a motor-vehicle or hotel tax onto a boat.
Example: Statewide 6% when no local is listed
Scenario: $40,000 dealer boat, no trade-in. The Tax Commission finder shows no local sales tax for that jurisdiction on the closing date.
Print or save the finder result with the invoice. Local options change.
Example: How to add a local rate after you look it up
Scenario: Same $40,000 boat. You look up the delivery city on the Tax Commission site and the finder returns a local sales tax. This page does not fill in that percentage.
Until the finder returns a number, budget the $2,400 state tax and ask the dealer or Commission whether local applies.
- Idaho State Tax Commission local rate tools (verify before closing)
- STC Sales of Boats and Trailers by Dealers (6% state)
ST-109, Parks registration, and title
Idaho Department of Parks and Recreation registers vessels through agents. On first registration or transfer, Form ST-109 documents that sales or use tax was paid or that an exemption applies, unless the county assessor collects the tax instead. Skipping ST-109 is a common miss: Parks can register only after the tax affidavit path is complete.
This page does not publish Parks numbering or title dollar amounts. The Tax Commission materials used here treat those fees as separate from sales tax and tell you to use the current Parks schedule. Ask Parks or the agent what you will pay to number the hull. Coast Guard documentation does not skip Idaho sales or use tax and does not skip Parks registration when Idaho requires it.
Example: Dealer already collected $2,400 — you still bring ST-109 facts to Parks
Scenario: Dealer charged $2,400 Idaho tax on a $40,000 boat. You go to a Parks agent to register.
Bring the dealer invoice. If tax was not collected, ST-109 is how the $2,400 (or other base) gets paid at the window.
Example: Private transfer — tax and Parks in one trip
Scenario: $15,000 private boat. No dealer. You and the seller meet at a Parks agent.
Budget the $900 as tax. Treat Parks fees as a second line you confirm the same day.
- IDAPA 35.01.02.113 — ST-109 on boat registration
- STC forms hub — ST-109, ST-104NR, ST-133
Nonresidents, military, family, and documented vessels
Form ST-104NR is the nonresident vessel exemption: immediate removal, register or title outside Idaho, and no more than 90 days of Idaho use in a 12-month period using 16-hour days. It covers vessels with a motor (any length) and vessels without a motor that are 11 feet or longer. A paddleboard or similar paddlecraft without a motor, bought in Idaho by a nonresident, does not qualify — it is taxable.
Military members who will use the boat in Idaho pay tax even if they are not Idaho residents. Do not assume orders equal $0.
Family and American Indian certificate paths exist on Form ST-133 for some vehicle and vessel contexts. Follow the Tax Commission exemption chart. This page does not auto-zero a gift, inheritance, or family transfer. If ST-133 applies to your facts, tax can be $0; if it does not, pay 6% (plus local if any). New-resident vehicle Form ST-102 themes should not be copied onto a boat until the Commission confirms they apply to vessels.
USCG documented boats remain subject to Idaho sales or use tax unless an exemption fits. Register with Parks when Idaho requires numbering.
Example: Qualifying ST-104NR versus a weekend paddleboard
Scenario A: Nonresident buys a 21-foot outboard from an Idaho dealer, completes ST-104NR, removes it immediately, registers it in another state, and will not use it in Idaho more than 90 16-hour days in 12 months. Scenario B: Nonresident buys a paddleboard with no motor in Idaho.
Length-and-motor tests matter. A kayak or paddleboard is not a free pass because you have an out-of-state driver’s license.
Example: Military member using the boat on an Idaho lake
Scenario: A service member stationed in Idaho, not an Idaho resident, buys a $40,000 boat to keep on a local reservoir. No ST-104NR because the boat will be used in Idaho.
Pay the $2,400 (plus any local). Ask the Tax Commission only if a different exemption on the chart actually matches your papers — not because of rank.
- STC dealer-sales page (ST-104NR tests; military use in Idaho is taxable; paddlecraft)
- STC forms: ST-104NR, ST-133, ST-101
How to calculate the tax you will owe
Start with the sales price the Tax Commission defines, including freight to the seller and options, keeping manufacturer rebates in. Subtract a retailer trade-in if the dealer takes the old boat into inventory at the sale. Do not subtract optional warranties, separately stated finance charges, or Parks title/registration. Multiply by 6% plus any local rate from the finder. Short-circuit to $0 only for a documented exemption (ST-104NR, ST-101, a qualifying ST-133, or another chart item the Commission accepts).
- Channel: dealer collect versus ST-109 at Parks.
- Build the base (rebate in; retailer trade-in out; no Parks fees in the base).
- Apply 6% plus verified local.
- Apply an exemption only when the named form matches the facts.
- Add Parks numbering from Parks — not from this page.
Example: Walkthrough of a dealer closing with trade-in and rebate
Scenario: $52,000 new boat, $2,000 manufacturer rebate, $10,000 retailer trade-in, Idaho resident, finder shows no local.
If you subtracted the rebate, you would underpay $120. Leave it in.
Example: Walkthrough of a nonresident who does not qualify
Scenario: Out-of-state buyer pays $40,000 at an Idaho dealer for a boat that will live on an Idaho lake all summer, far beyond 90 days. No military exemption. No local on the finder.
Buying as a nonresident is not enough. The 90-day clock and immediate removal are the tests.
- STC Sales of Boats and Trailers by Dealers; ST-104NR instructions
What this page does not estimate
This page estimates 6% Idaho sales and use tax on the Commission’s base. It does not publish Parks & Recreation registration or title dollars. It does not assign a local city or county percentage. It does not treat Form ST-102 new-resident vehicle rules as a boat wipe. It does not auto-zero gifts or inheritances. It does not exempt military use in Idaho. It does not pull manufacturer rebates out of the price. It does not exempt a nonresident paddlecraft without a motor.
Example: Parks fees stay off this tax total
Scenario: $40,000 dealer boat, $2,400 Idaho tax. The agent also quotes a numbering fee.
Ask the agent for today’s Parks schedule before you wire funds.
Example: Family transfer — chart first, not $0 by default
Scenario: A parent transfers a $25,000 boat to an adult child.
Bring ST-133 only if the chart says your relationship and facts qualify. Otherwise budget $1,500 plus Parks.
Two complete buying examples
Complete example 1: Cascade resident, dealer runabout
Scenario: Idaho resident. Dealer boat $40,000. Retailer trade-in $8,000. No manufacturer rebate. Finder shows no local. Boat stays in Idaho.
If a quote pulled a $2,000 rebate out of a similar deal, that quote used the wrong base. If a quote skipped tax because the buyer “is from out of town,” that quote skipped ST-104NR’s tests.
Complete example 2: Private lake boat plus a nonresident who qualifies
Scenario A: Idaho buyer, private $15,000, 18-foot outboard, ST-109 at Parks. Scenario B: Nonresident buys a $40,000 motorboat from an Idaho dealer, meets every ST-104NR test, copies the form as required.
Scenario A’s $900 is why “I bought it used” is not a plan. Scenario B’s $0 is narrow: motor (or sail/hull ≥11 feet without motor), immediate removal, out-of-state title or registration, 90-day cap.
Common questions
Is Idaho boat tax 6%?
Yes, the state sales and use rate is 6%. Add local only after the Tax Commission finder says so.
Does a manufacturer rebate lower tax?
No. The rebate stays in the sales price. A retailer trade-in is what reduces the base.
I am in the military. Is the boat exempt?
Not if you will use it in Idaho. Pay 6% (plus local if any) unless a different chart exemption actually fits.
Are private sales tax-free?
No. Expect 6% at registration on ST-109 unless an exemption applies.
Can a nonresident skip tax on a kayak?
Not on a paddlecraft without a motor bought in Idaho. ST-104NR does not cover that.
What is ST-109?
The boat registration affidavit used at first registration or transfer so Parks (or the assessor) can see that tax was paid or exempted.
Example: $40,000 documented cruiser kept in Idaho
Scenario: Coast Guard–documented 36-foot boat, $40,000, Idaho dealer, resident buyer, no trade-in, no local on the finder.
A federal document is not an Idaho tax holiday.
Example: Government or school purchase on ST-101
Scenario: A qualifying government unit buys a $40,000 patrol boat with a completed ST-101.
Entity certificates are not transferable to a neighbor’s recreational purchase.
Before you sign
- Compute 6% on the Commission’s sales price, with manufacturer rebates left in.
- Subtract only a retailer trade-in taken into inventory at the sale.
- Run the Tax Commission local finder; do not guess a city rate.
- Military use in Idaho is taxable.
- ST-104NR needs immediate removal, out-of-state registration or title, and the 90-day test — not a paddleboard without a motor.
- Private buyers should expect ST-109 and 6%, not a casual holiday.
- Ask Parks for numbering fees. They are not in this tax total.
- Family or tribal claims belong on ST-133 only if the chart says so.
Official references
- Sales of Boats and Trailers by Dealers (base, trade-in, rebate, nonresident, military)
- Sales and use forms hub (ST-104NR, ST-109, ST-133)
- IDAPA 35.01.02.113 (ST-109 at boat registration)
This page estimates Idaho boat sales and use tax at the 6% state rate. The Idaho State Tax Commission sets the tax, including any local sales tax the finder lists. The Idaho Department of Parks and Recreation (or your county assessor, when that office collects) sets registration, title, and the ST-109 window.