State comparison · Updated October 2026
Iowa vs. Missouri Driving Laws (2026)
Iowa and Missouri differ on 6 of 9 rules we track: max speed limit, learner's permit age, car insurance, car sales tax, car inspection and helmet law.
Heading from Des Moines to Kansas City takes you across the border, and 6 of the laws differ once you cross. Main routes include I-80 on the Iowa side and I-70 on the side of Missouri; the capitals, Des Moines and Jefferson City, write the laws for their side.
The biggest gap: top speed limits differ by 5 mph different. People who live in Cedar Rapids heading to St. Louis, and back, deal with both sets of rules: Iowa's on I-35 and Missouri's once they cross on I-44. Use the Iowa vs Missouri guide when moving from Des Moines and Kansas City.
On a weekend drive from Des Moines to Jefferson City, keep a helmet if you ride, plan the route before leaving, and expect the limit to change from 70 to 75 mph after crossing.
| Topic | Iowa | Missouri |
|---|---|---|
| Max speed limit | 70 mph | 75 mph |
| Phone law | Hands-free law | Hands-free law |
| Learner's permit age | Permit at 14 | Permit at 15 |
| Car insurance | 20/40/15 | 25/50/25 |
| Car sales tax | 5% | 4.225% |
| Car inspection | No regular inspection | Safety + emissions |
| New resident deadline | 30 days | 30 days |
| Helmet law | No helmet law | Under 26 |
| Lane splitting | Not allowed | Not allowed |
Driving laws side by side: Iowa vs Missouri
Iowa vs Missouri: Iowa and Missouri match on phone law: Hands-free law.
Speed limits: Iowa vs Missouri
Missouri is faster on max speed limit, with Iowa with 70 mph and Missouri at 75 mph. Rural interstates reach 70 mph in Iowa and 75 mph in Missouri. Leaving Des Moines toward Kansas City, expect the limit to change at the state line.
Learner's permit age: Iowa vs Missouri
The rule is earlier in Iowa on learner's permit age, with Iowa at permit at 14 and Missouri with permit at 15. Young motorists in Des Moines taking a trip to Kansas City follow Missouri's permit rules there.
Owning a car: Iowa vs Missouri
Iowa vs Missouri: Iowa and Missouri agree on new resident deadline (30 days).
Minimum car insurance requirements: Iowa vs Missouri
Missouri is higher on car insurance, with Iowa at 20/40/15 and Missouri at 25/50/25. Iowa is at-fault while Missouri is at-fault. A policy written in Des Moines must be switched when you settle in Kansas City.
Car sales tax: Iowa vs Missouri
The law is higher in Iowa on car sales tax, with Iowa at 5% and Missouri at 4.225%. On a $30,000 car, state tax is about $1,500 in Iowa versus $1,268 in Missouri. Shoppers in Cedar Rapids and St. Louis owe the tax based on their registration address, wherever they buy.
Vehicle inspection and emissions testing: Iowa vs Missouri
The law is stricter in Missouri on car inspection, with Iowa at no regular inspection and Missouri at safety + emissions. A car registered in Cedar Rapids answers to Iowa rules, even on trips to St. Louis.
Motorcycle compared: Iowa vs Missouri
Iowa vs Missouri: Iowa and Missouri agree on lane splitting (Not allowed).
Motorcycle helmet laws: Iowa vs Missouri
The rule is stricter in Missouri on helmet law, with Iowa at no helmet law and Missouri with under 26. Riders heading from Des Moines into Kansas City fall under Missouri's helmet rule at the border.
Moving or buying across the border
- Iowa vs Missouri: moving from Iowa to Missouri gives you 30 days to register the car and 30 days for a license.
- Moving from Missouri to Iowa: 30 days for registration and no fixed license deadline.
Iowa vs Missouri: common questions
Which has the higher speed limit, Iowa or Missouri?
Missouri (75 mph vs. 70 mph).
Is it cheaper to buy a car, Iowa or Missouri?
Missouri charges less at the state level (5% vs. 4.225%).
Is a motorcycle helmet required in both Iowa and Missouri?
Iowa: No helmet law; Missouri: Under 26.