A Colorado gun background check runs through the state’s own InstaCheck system, operated by the Colorado Bureau of Investigation, and every firearm sale in the state has to go through it. CBI checks state and federal databases, charges a $15 fee, and clears most buyers within minutes. You must be at least 21, and even after CBI approves you, a mandatory waiting period of at least three days applies before the dealer can hand over the gun.
How InstaCheck Works
When you buy a firearm from a licensed Colorado dealer, the dealer submits your information electronically to CBI rather than to the federal NICS system used in many other states.1Colorado Bureau of Investigation. Firearms InstaCheck searches criminal history records, protection orders, mental health commitments, and other state and federal sources. If nothing disqualifying turns up, CBI approves the transfer. If a record flags your name, CBI denies it.
Most checks finish within minutes. Some require more investigation, and when CBI can’t immediately approve or deny, the review can stretch past three business days. Federal rules give a dealer discretion to release the firearm after three business days without a response, but CBI encourages dealers to wait for a complete answer.2Colorado Bureau of Investigation. InstaCheck Numbers Remain Elevated That three-business-day clock runs Monday through Friday and excludes holidays.
CBI charges a $15 fee for each background check as of March 1, 2025.3Colorado Crime Information Center. InstaCheck The fee applies to both dealer sales and private transfers processed through a dealer, and the dealer may add its own service fee on top.
The Three-Day Waiting Period
Colorado law requires a waiting period before a dealer can release a purchased firearm. The wait is the later of three days after the background check is initiated or whenever CBI actually approves the check.4Colorado General Assembly. HB23-1219 Waiting Period To Deliver A Firearm Approval in ten minutes still means a three-day wait. Approval in five days means a five-day wait.
The waiting period does not apply to antique firearms, curios or relics, or to transfers by a military member deploying outside the country within 30 days to an immediate family member.
Who Can Buy a Firearm in Colorado
You must be at least 21 to buy any firearm in Colorado, handgun or long gun. SB23-169, enacted in 2023, raised the previous minimum age of 18, and the rule applies to both dealer and private sales.5Colorado General Assembly. SB23-169 Increasing Minimum Age To Purchase Firearms The narrow exceptions cover active-duty military, peace officers, and individuals certified by the Peace Officer Standards and Training Board, all while acting in their official capacity.
You need a valid government-issued photo ID for identity and residency. Federal law limits handgun sales by licensed dealers to residents of the dealer’s state, so handgun buyers need documentation showing Colorado residency. Long guns can be sold to residents of other states, provided the sale complies with the laws of both Colorado and the buyer’s home state.
A Colorado concealed handgun permit does not exempt you from a background check. CBI requires a fresh check for every firearm purchase, even for permit holders, and out-of-state concealed carry permits receive the same treatment.6Colorado Bureau of Investigation. Concealed Handgun Permit (CHP)
What Will Cause a Denial
CBI checks both federal and Colorado disqualifiers on every purchase. A prohibition under either system results in a denial.
Federal Prohibitions
Under 18 U.S.C. ยง 922(g), federal law bars firearm possession by anyone convicted of a crime punishable by more than one year in prison; fugitives from justice; unlawful users of controlled substances; people found mentally incompetent by a court or involuntarily committed; certain non-citizens; people dishonorably discharged from the military; those who have renounced U.S. citizenship; people subject to qualifying domestic protection orders issued after a hearing; and anyone convicted of a misdemeanor crime of domestic violence involving the use or attempted use of physical force.7Office of the Law Revision Counsel. 18 U.S. Code 922 – Unlawful Acts
Colorado Additions
Colorado layers additional restrictions on top. A conviction for any felony in Colorado or another state bars firearm possession.8Justia. Colorado Code 18-12-108 – Possession of Weapons by Previous Offenders
Colorado also denies transfers to people convicted of certain misdemeanors committed on or after June 19, 2021, if the conviction occurred within the last five years, including violations of domestic-violence-related protection orders.9Colorado Bureau of Investigation. State and Federal Firearm Prohibitors The five-year lookback can catch state offenses that would not meet the federal domestic-violence definition.
Colorado’s red flag law adds another route to denial. A court can issue a temporary extreme risk protection order lasting up to 14 days, and after a hearing, a full ERPO lasting up to 364 days.10Colorado Department of Public Health and Environment. Extreme Risk Protection Orders While the order is in force, the person cannot buy or possess firearms and must surrender any they already own.
Marijuana and Other Controlled Substances
Marijuana is legal under Colorado law but remains federally controlled, and federal law prohibits any “unlawful user of or addicted to” a controlled substance from possessing firearms.7Office of the Law Revision Counsel. 18 U.S. Code 922 – Unlawful Acts A Colorado medical card does not shield you. Regular marijuana users can be denied.
ATF revised its definition of “unlawful user” in January 2026 to require evidence of regular use over an extended period continuing into the present, rather than older inference-based criteria such as a single drug arrest or positive drug test.11Federal Register. Revising Definition of Unlawful User of or Addicted to Controlled Substance Isolated or sporadic use no longer qualifies. Daily or weekly use sustained over months still does.
Private Sales Between Individuals
Colorado requires nearly all private firearm transfers to go through a licensed dealer who runs an InstaCheck, just like a retail sale. The buyer and seller meet at a dealer, the dealer submits the check, and the transfer only completes if CBI approves.12Justia. Colorado Code 18-12-112 – Private Firearms Transfers – Sale and Purchase – Background Check Required – Penalty – Definitions If the buyer is denied, the seller keeps the firearm. The $15 CBI fee applies, and the dealer can charge an additional service fee.3Colorado Crime Information Center. InstaCheck
Several private transfers are exempt from the background check requirement:12Justia. Colorado Code 18-12-112 – Private Firearms Transfers – Sale and Purchase – Background Check Required – Penalty – Definitions
- Gifts or loans between immediate family, including spouses, parents, children, siblings, grandparents, grandchildren, nieces, nephews, first cousins, aunts, and uncles.
- Antiques and curios or relics as defined under federal law.
- Transfers at death through an estate or a trust created by a will.
- Temporary loans in someone’s home for self-defense, when the recipient is not a prohibited person and reasonably believes a firearm is needed to prevent imminent death or serious injury.
- Temporary possession at an organized shooting range or sanctioned competition.
- Temporary loans for legal hunting, fishing, target shooting, or trapping, if the borrower holds any required license.
- Transfers for repair or maintenance to a person who can legally possess a firearm.
- Any temporary transfer while the owner remains physically present.
- Temporary transfers of up to 72 hours without a check, though the transferor may share liability if the recipient uses the firearm unlawfully.
- Transfers by a service member deploying outside the country within 30 days to immediate family.
If You Are Denied
Denials sometimes come from outdated records, mistaken identity, or data-entry errors rather than an actual disqualifier. You have 30 days from the date of the denial to begin an appeal with CBI.13Colorado Bureau of Investigation. Appeals Information The fastest route is CBI’s online appeal portal, but a paper form works too. CBI may ask for a full set of inked fingerprints so it can compare them against the record that triggered the denial.14Colorado Bureau of Investigation. Appeal of Firearm Denial
If your denial rests on a record that has been sealed, expunged, or corrected, gather the court orders before you file so CBI can see the problem right away. If CBI upholds the denial after review, further options may be available in court, and an attorney familiar with firearms law can walk you through them.
Penalties for Lying or Buying for Someone Else
Lying on the ATF Form 4473 about your identity, criminal history, drug use, or any other question is a serious offense. Under Colorado law, knowingly providing false information to acquire a firearm in a private transfer is a class 2 misdemeanor and bars firearm possession for two years after conviction.15Colorado Bureau of Investigation. C.R.S. 18-12-112 Federally, a false statement on Form 4473 can bring up to 10 years in federal prison, and federal prosecutors have been pursuing these cases more aggressively.16Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF). Federal Prosecutors Aggressively Pursuing Those Who Lie in Connection With Firearm Transactions
Buying a firearm on behalf of a prohibited person is a straw purchase, illegal under both state and federal law. The Bipartisan Safer Communities Act of 2022 created a standalone federal straw-purchase offense carrying up to 25 years in prison and fines of up to twice the gross profits from the illegal transaction.17Federal Register. Bipartisan Safer Communities Act Conforming Regulations