Idaho vs Montana
Idaho and Montana compare differently in the short vs long run: Idaho costs $2,182 first year ($68 annual after), Montana costs $412 first year ($385 annual after).
Cost comparison
| Idaho | Montana | Difference | |
|---|---|---|---|
| First-year total All-in cost to register a new $35,000 gas vehicle for the first time, including sales tax, title, and registration. | $2,182 | $412 | +$1,770 |
| Annual renewal (year 2+) Recurring annual cost after the first year — what you actually pay every year you own the car. | $68 | $385 | −$318 |
| Sales tax (one-time) Sales/use/excise tax owed at purchase on a $35,000 vehicle, using typical local rates. | $2,100 | $0 | +$2,100 |
| Combined sales tax rate State rate plus typical local rate (where applicable). | 6.00% | 0.00% | +6.00 pp |
| EV first-year total Same $35K scenario but as a battery electric vehicle, capturing EV-specific surcharges. | $2,322 | $542 | +$1,780 |
| EV annual renewal Recurring EV-ownership cost in year 2+. | $208 | $515 | −$308 |
| EV surcharge Annual EV-specific registration fee (zero in states without one). | $140 | $130 | +$10 |
How each state structures it
Idaho
Idaho has one of the simpler vehicle cost structures in the West: age-tiered registration ($48 for vehicles 1-2 years old, dropping to $36 then $24 as they age), 6% state sales tax with NO local additions, no annual ad valorem on vehicles, and no state-mandated emissions testing (eliminated July 2023). Title fee is just $14, and there's a small county admin fee ($5-12 depending on county). EV surcharge is $140/year (hybrid $75). A new $35,000 vehicle in Ada County (Boise) runs about $2,250 in first-year costs, dominated by the $2,100 sales tax. Annual renewals are just $67.50.
Montana
Montana is one of only FIVE US states with no general sales tax — making vehicle purchases tax-free regardless of price. Age-tiered registration is $217/year for new vehicles (0-4 years old), dropping to $87 (5-10 years) and $28 (11+ years). 45 of Montana's 56 counties impose a 0.5% county option tax on depreciated MSRP — about $175/year for a $35,000 new vehicle. A "luxury surcharge" of $825/year applies to vehicles with MSRP over $150,000 that are 10 years old or less. Title fee is $10 + $10 Highway Patrol fee. Montana has no EV surcharge. A new $35,000 vehicle in Montana (participating county) runs about $412 in first-year costs — among the lowest in the US (the no-sales-tax savings is $2,100+ vs neighbors). Annual renewals around $392.
What this means for you
- Buying a new car: Montana is roughly $1,770 cheaper than Idaho in the first year on a $35K vehicle, driven mostly by sales tax and one-time fees.
- Annual renewal: Idaho is cheaper to renew annually by about $318/year. Over a 5-year ownership period that's roughly $1,588 in renewal-fee savings alone.
- If you drive an EV: Both states charge similar EV surcharges (Idaho: $140/year, Montana: $130/year), so EV ownership cost between the two is comparable.
- Structural differences: Neither state imposes an annual ad valorem vehicle property tax, so renewal costs stay relatively flat after the first year for both.
Frequently asked questions
Is it cheaper to register a car in Idaho or Montana?
It depends on the timeframe. Idaho costs $2,182 first year and $68 annually after. Montana costs $412 first year and $385 annually after. One state may be cheaper upfront and the other cheaper long-term.
What is the sales tax difference between Idaho and Montana?
Idaho charges 6.00% combined sales tax on vehicles; Montana charges 0.00%. On a $35,000 purchase that's $2,100 in Idaho vs $0 in Montana.
Do Idaho and Montana both charge EV registration fees?
Idaho: $140/year EV surcharge. Montana: $130/year EV surcharge. EV fees are added on top of standard registration costs.
Official sources: Idaho Transportation Department • Montana Motor Vehicle Division
Data last updated: 2026-05-23