Idaho Knife Laws
Idaho does not limit blade length for ordinary carry, and permitless carry starts at 18. Six inches is the number that matters inside a courthouse, jail or juvenile detention facility, where a longer concealed blade is barred. Automatic knives have never been restricted. Since 1 July 2024 the state has had knife preemption, so a city cannot write its own rule and older articles about city limits are out of date.
This is not legal advice, and we are not lawyers. It is a plain reading of published summaries and the statutes they cite, kept current on a fixed schedule. Local ordinances are frequently stricter than state law and are not all captured here. Check the statute, and check your city, before you carry.
Recent change. 2025 – SB 1027, first-in-nation debanking protection for the knife industry.
Idaho knife law at a glance
| Concealed carry blade limit | No blade length governs for ordinary carry. Six inches is the number that matters in a courthouse, jail or juvenile detention facility, where a longer concealed blade is barred. Permitless carry applies from 18. |
|---|---|
| Automatic and switchblade knives | Legal. No restriction has ever been enacted. |
| Knife types banned outright | None outright. |
| Statewide preemption | Yes, since 1 July 2024. A city, county or district may not make its own knife rule or tax. |
| The statutes | Idaho Code 18-3302, 18-3302A through 18-3302E and 18-3303 — read them |
Source last revised 20 August 2024
Last known change 2025
Next review 15 November 2026
How fresh this is, and how you can tell
Two dates sit above, and they are not the same thing. Checked by us is the last time a person went back to the sources and confirmed this page still matches them. Source last revised is when the American Knife and Tool Institute last updated its own Idaho page. A 2021 revision date is not automatically wrong — it usually means nothing has changed since — but it does mean nobody had looked recently, and that is exactly the gap this page exists to close.
Crossing the Idaho state line
Knife law stops at the border and the next state does not have to agree with this one. If you drive, these are the states you are most likely to carry into, and what changes when you do.
| State | Automatic knives | Concealed blade limit |
|---|---|---|
| Washington | Restricted or banned | No blade length. The offense turns on the circumstances of possession. |
| Oregon | Legal | No blade length governs the concealed carry offense itself, but a pocketknife under four inches is excepted in restricted places. |
| Nevada | Legal | No blade length governs statewide, except that a machete may not be carried concealed. The county rule is the one that catches visitors. |
| Utah | Legal | No blade length governs and concealment is not an issue. |
| Wyoming | Legal | No blade length governs, and open carry is unrestricted. The concealed deadly weapon rule carries exceptions from 21 for people without violent crime or drug convictions. |
| Montana | Legal | No blade length governs. Montana retitled its concealed weapon law in 2017 to cover firearms, so any knife may be carried openly or concealed. |
A knife that is lawful in your pocket at home can be unlawful the moment you cross, and nobody stops you at the line to tell you. The map for all fifty states covers the rest.
Common questions about Idaho knife laws
What size knife is legal to carry in Idaho?
No blade length governs for ordinary carry. Six inches is the number that matters in a courthouse, jail or juvenile detention facility, where a longer concealed blade is barred. Permitless carry applies from 18.
Are switchblades legal in Idaho?
Legal. No restriction has ever been enacted.
Which knives are banned outright in Idaho?
None outright.
Does Idaho have knife preemption?
Yes. Idaho has statewide preemption, which means a city cannot write its own stricter knife ordinance. One rule covers the whole state, and that is most of what preemption is worth.
Can I keep a knife in my car in Idaho?
Where a state has a concealed carry limit, a knife in a glovebox or a door pocket is generally treated as concealed. Read the concealed line above and apply it to the vehicle. If that line says concealment is not the issue in this state, the vehicle is not the issue either — but where you drive to still is, because schools and courthouses are barred everywhere.
Where this comes from
Two independent sources, cross-checked against each other, and the statute text where they disagree. The automatic knife column is the American Knife and Tool Institute’s state automatics table, checked against Knife Rights’ own switchblade legality table and their legislative update log. Everything on a state page is quoted or closely tracked from that state’s AKTI page, and we print the date AKTI last revised it so you can see for yourself how fresh the underlying work is.
Where a source is older than a change we know about, we say so on the page rather than quietly leaving the old answer up. That is the whole reason this is checked every two months.
Elsewhere on Popular EDC
The knife law map for all fifty states, the knife steel comparison chart for choosing the blade itself, and every Popular EDC tool in one place.
Data updated September 2026. Idaho knife law checked against the published sources on 15 September 2026, and due for review again on 15 November 2026.