Buying a gun in Colorado: background checks, waiting period, age, and taxes
Last verified against primary sources: · Updated
To buy a gun in Colorado you must be 21, pass a background check, and wait the required period before the dealer can deliver it. A background check is required on every sale, including private ones, which must run through a licensed dealer (C.R.S. § 18-12-112). The dealer cannot hand the gun over until the later of three days after the check starts or when it is approved (§ 18-12-115). On top of that, Colorado now layers a 6.5% excise tax, a state dealer permit, new ammunition rules, and — from August 1, 2026 — a safety-course requirement to buy certain semiautomatic firearms.
Universal background checks — including private sales
Since July 1, 2013, nearly every firearm transfer in Colorado requires a background check, and a private (non-dealer) sale must be routed through a licensed gun dealer who obtains that check from the Colorado Bureau of Investigation (CBI):
shall not accept possession of the firearm unless the prospective firearm transferor has obtained approval of the transfer from the bureau.
An approved transfer is valid for 30 calendar days. A dealer may charge up to a $10 statutory fee to facilitate a private transfer, and CBI charges its own background-check fee (raised to $15 effective March 1, 2025). A handful of transfers are exempt from the check — immediate family, antiques and curios/relics, brief loans of 72 hours or less, supervised range/competition/hunting transfers, gunsmithing, and a deploying service member's transfer to family. Violating the requirement is a class 2 misdemeanor carrying a two-year possession ban. Full detail: do private gun sales need a background check?
The 3-day waiting period
A dealer cannot deliver a gun until the waiting period ends:
the later in time of 3 days after the initiation of a required background check of the purchaser or when the purchase is approved following any background check.
So the wait is at least three days, and longer if the check is not approved within three days. Antiques/curios and a deploying service member's family sale are exempt, as is any transfer that does not legally require a check. Delivering early is a civil infraction ($500 first offense; $500–$5,000 after). See is there a waiting period in Colorado? for the litigation status.
Waiting-period litigation. The waiting period is being challenged in Garcia v. Polis (D. Colo.). A preliminary injunction was denied in November 2023 and the law has been enforced continuously since; the case remains pending. As of our July 20, 2026 check it is in force. This area moves fast — we re-verify and date it.
You must be 21 to buy
SB23-169 raised the minimum age to purchase any firearm in Colorado from 18 to 21, with exceptions for active-duty U.S. armed-forces members and peace officers or P.O.S.T.-certified persons. It was signed April 28, 2023 and took effect August 7, 2023. An under-21 purchase, or facilitating one, is a class 2 misdemeanor.
Age-21 litigation history. SB23-169 was preliminarily enjoined on August 7, 2023, the day it was to take effect. But on November 5, 2024, the Tenth Circuit reversed and dissolved the injunction, holding that age conditions on the commercial sale of arms are "presumptively lawful." As of our July 20, 2026 check the age-21 requirement is in force and enforceable. See can an 18-year-old buy a gun in Colorado? — and note that possessing a firearm at 18 is treated separately from buying one.
The store needs a Colorado dealer permit
Beginning July 1, 2025, every firearms dealer must hold a Colorado state permit — separate from the federal FFL — to do business, under HB24-1353 (codified at C.R.S. § 18-12-401.5), administered by the Department of Revenue. The permit fee is $400 for a permit issued on or before June 30, 2026, and eligibility requires a valid federal firearms license and a clean recent firearms-law record. Dealing without a permit is an unclassified felony (fine up to $250,000). A 2025 effort to repeal the requirement, HB25-1055, failed in committee, so the permit stands.
The 6.5% excise tax (Proposition KK)
Colorado voters approved Proposition KK (referred by HB24-1349) in November 2024, imposing a 6.5% state excise tax on retail sales of firearms, firearm precursor parts, and ammunition, effective April 1, 2025 (codified in C.R.S. Title 39, Article 37, §§ 39-37-101 et seq.). The tax is levied on the vendor — dealers, manufacturers, and ammunition sellers — and is typically passed through to the buyer at the register. Sales to a peace officer, a law-enforcement agency, or an active-duty member of the armed forces are exempt. A small-seller threshold applies: a vendor is not required to register and collect the tax until its Colorado retail firearm/parts/ammunition sales exceed $20,000 in a calendar year, and private-party sales are not taxed at all.
New ammunition rules (HB25-1133)
Colorado's ammunition-sale law, HB25-1133, took effect July 1, 2026. It prohibits the retail sale of ammunition to anyone under 21 and requires sellers to verify age with a valid government-issued photo ID, and it requires ammunition to be stored so a buyer cannot access it without the vendor's assistance (locked case or behind the counter). The law provides exemptions for certain groups. Penalties escalate from a civil infraction for a first violation to a class 1 misdemeanor for a second or subsequent one. Colorado does not run a background check specifically for ammunition purchases, but as of July 1, 2026 it does require this age-21 verification and secure in-store display.
Why we cite the bill, not a section number. The exact codified C.R.S. section for HB25-1133 could not be verified against the enacted text in our research pass, and the finer ammunition exemptions were sourced only from secondary material. We state only what was corroborated (age-21 verification, secure display, effective date, penalty tier) and cite the bill itself.
Gun shows
Colorado applies its background-check requirement specifically at gun shows:
no firearm shall be transferred unless a background check has been obtained by a licensed gun dealer.
A gun-show vendor must require that a background check "be conducted of the prospective transferee" and obtain CBI approval, and the show's promoter must "arrange for the services of one or more licensed gun dealers on the premises" to run those checks. A violation is a class 1 misdemeanor. Separately, HB25-1238 added gun-show security and safety requirements (such as insurance, a security plan, signage, and surveillance) effective January 1, 2026.
The August 1, 2026 layer: specified semiautomatic firearms
On top of everything above, from August 1, 2026, buying most detachable-magazine semiautomatic rifles and shotguns, and gas-operated semiautomatic handguns, requires the buyer to have completed a state-verified firearms safety course under SB25-003 (C.R.S. § 18-12-116). Owning guns you already have stays legal, and there is no registration requirement. Most traditional recoil-operated handguns and all manual-action long guns are unaffected. Full detail: Colorado's new gun law — what changes August 1, 2026.
Common questions
What do you need to buy a gun in Colorado?
You must be at least 21, pass a background check (required on every sale, including private ones routed through a licensed dealer), and wait out the required period — the later of three days after the check starts or when it is approved — before the dealer can deliver the firearm.
Do all gun sales in Colorado require a background check?
Yes, with limited exemptions. Private sales must run through a licensed dealer for a CBI background check under C.R.S. § 18-12-112. Exempt transfers include those between immediate family, antiques and curios/relics, and loans of 72 hours or less.
How much tax do you pay on a gun in Colorado?
Colorado imposes a 6.5% state excise tax on retail sales of firearms, precursor parts, and ammunition, effective April 1, 2025 (Proposition KK). It is levied on the vendor and generally passed to the buyer. Sales to law enforcement and active-duty military are exempt, and private-party sales are not taxed.
Can you buy ammunition in Colorado at 18?
Generally no. As of July 1, 2026, HB25-1133 prohibits retail ammunition sales to anyone under 21 and requires photo-ID age verification, with some exemptions for certain groups. Ammunition must also be kept in secure display that requires vendor assistance to access.
Is there a waiting period to buy a gun in Colorado?
Yes. A dealer may not deliver a firearm until the later of three days after the background check is initiated or when it is approved (C.R.S. § 18-12-115), so the wait is a minimum of three days and longer if the check is not yet approved.
Do gun stores in Colorado need a special permit?
Yes. Since July 1, 2025, dealers must hold a Colorado state dealer permit (HB24-1353, C.R.S. § 18-12-401.5) in addition to their federal FFL, administered by the Department of Revenue, with a $400 fee. Dealing without one is an unclassified felony.
Primary sources for this page
- C.R.S. § 18-12-112 — Colorado Revised Statutes (colorado.public.law)
- C.R.S. § 18-12-115 — Colorado Revised Statutes (colorado.public.law)
- C.R.S. § 18-12-501 — Colorado Revised Statutes (colorado.public.law)
- SB23-169 (minimum age to purchase) — Colorado General Assembly
- HB24-1353 (state dealer permit) — Colorado General Assembly
- HB24-1349 / Proposition KK (excise tax) — Colorado General Assembly
- HB25-1133 (ammunition sales) — Colorado General Assembly
- HB25-1238 (gun-show requirements) — Colorado General Assembly