A Colorado gun background check runs through the Colorado Bureau of Investigation’s InstaCheck system every time you buy a firearm, whether from a licensed dealer or a private seller. The check costs $15, you must be at least 21, and the dealer cannot hand over the firearm until at least three days after the check started, even if CBI approves you in minutes.
How InstaCheck Works
Colorado does not rely solely on the federal NICS system. Instead, CBI operates its own InstaCheck unit, which queries state and federal databases together: criminal history, protection orders, mental health commitments, and the federal records NICS would otherwise check.1Colorado Bureau of Investigation. Firearms The dealer submits your information electronically after you fill out ATF Form 4473. CBI either approves the transfer, denies it, or holds it open for further investigation.
Most checks finish within minutes. Some don’t. When CBI cannot immediately resolve a check, the review can run past three business days. Federal rules give a dealer discretion to release the firearm after three business days without a response, but CBI asks dealers to wait until the check is actually complete.2Colorado Bureau of Investigation. InstaCheck Numbers Remain Elevated The three-business-day clock runs Monday through Friday and skips holidays.
A Colorado concealed handgun permit does not get you out of the check. CBI requires a new InstaCheck for every purchase, and the same goes for out-of-state concealed carry permit holders.3Colorado Bureau of Investigation. Concealed Handgun Permit (CHP)
The $15 Fee
CBI charges $15 for each background check, effective March 1, 2025.4Colorado Crime Information Center. InstaCheck The fee applies to dealer sales and to private transfers processed through a dealer. A dealer handling a private transfer may also charge a separate service fee that varies from shop to shop.
The Three-Day Waiting Period
Even an instant approval does not mean an instant purchase. Colorado requires a waiting period equal to the later of three days after the check is initiated or whenever CBI actually approves it.5Colorado General Assembly. HB23-1219 Waiting Period To Deliver A Firearm If CBI clears you in ten minutes, you still wait three days. If CBI takes five days to clear you, you wait five days.
The waiting period does not apply to antique firearms, curios or relics, or transfers by a military member deploying outside the country within 30 days to an immediate family member.
Who Can Legally Buy
You must be at least 21 to buy any firearm in Colorado, handgun or long gun. SB23-169 raised the minimum age from 18 in 2023, and the rule applies to both dealer and private sales.6Colorado General Assembly. SB23-169 Increasing Minimum Age To Purchase Firearms The exceptions are narrow: active-duty military, peace officers, and individuals certified by the Peace Officer Standards and Training Board, each only while acting in their official capacity.
You need a valid government-issued photo ID. 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 across state lines, but the sale has to comply with the laws of both Colorado and the buyer’s home state.
Who Gets Denied
CBI checks both federal and Colorado prohibitor lists. A disqualification under either one is enough to stop the sale.
Federal Disqualifiers
Under 18 U.S.C. § 922(g), nine categories of people are barred from receiving firearms:7Office of the Law Revision Counsel. 18 U.S. Code 922 – Unlawful Acts
- Anyone convicted of a crime punishable by more than one year in prison, in any court.
- Fugitives from justice.
- Unlawful users of a controlled substance.
- Anyone found mentally incompetent by a court or involuntarily committed.
- People unlawfully present in the U.S. or admitted on most nonimmigrant visas.
- Anyone discharged from the military under dishonorable conditions.
- Former citizens who renounced their citizenship.
- Anyone subject to a qualifying protection order restraining them from threatening an intimate partner or child, where the order followed a hearing with notice.
- Anyone convicted of a misdemeanor crime of domestic violence involving use or attempted use of physical force.
Colorado’s Additional Disqualifiers
Colorado adds its own restrictions. A conviction for any felony in Colorado or another state bars firearm possession, and the possession offense itself is a class 5 felony.8Justia. Colorado Code 18-12-108 – Possession of Weapons by Previous Offenders Using or threatening to use a firearm while committing that possession offense makes probation unavailable and triggers a mandatory prison sentence.
Colorado also denies transfers to people convicted of certain misdemeanors committed on or after June 19, 2021, if the conviction occurred in the previous five years. These include violations of protection orders related to domestic violence.9Colorado Bureau of Investigation. State and Federal Firearm Prohibitors
Extreme Risk Protection Orders
Colorado’s red flag law lets a court issue an extreme risk protection order temporarily barring someone from buying or possessing firearms. A temporary ERPO lasts up to 14 days. After a hearing, a full ERPO can last up to 364 days, during which the subject must surrender firearms and cannot buy new ones.10Colorado Department of Public Health and Environment. Extreme Risk Protection Orders
Marijuana Is Still a Problem
Marijuana is legal under Colorado law and remains a federally controlled substance. That contradiction matters at the sales counter, because federal law prohibits anyone who is an “unlawful user of or addicted to” a controlled substance from receiving a firearm.7Office of the Law Revision Counsel. 18 U.S. Code 922 – Unlawful Acts A Colorado medical card does not protect you from denial.
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 inferring use from a single 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. Someone using marijuana daily or weekly over months still does.
Buying From a Private Seller
Colorado requires nearly all private firearm transfers to go through a licensed dealer. You and the seller meet at a dealer, the dealer runs InstaCheck, and the transfer only happens if CBI approves.12Justia. Colorado Code 18-12-112 – Private Firearms Transfers – Sale and Purchase – Background Check Required – Penalty – Definitions If you’re denied, the seller keeps the firearm. The $15 CBI fee applies, and the dealer can add a service fee on top.
A handful of private transfers do not require a check:
- Gifts or loans between immediate family: 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 testamentary trust.
- A temporary loan in someone’s home for self-defense, if the recipient is not prohibited and reasonably believes it is necessary to prevent imminent death or serious injury.
- Temporary possession at an organized range or sanctioned shooting competition.
- Temporary loans while legally hunting, fishing, target shooting, or trapping, if the borrower holds any required license.
- Transferring a firearm for repair to someone who can legally possess it.
- Any temporary transfer while the owner remains physically present.
- Temporary transfers of up to 72 hours, with the transferor jointly liable if the recipient uses the firearm unlawfully.
- Transfers by a service member deploying outside the country within 30 days to immediate family.
If You’re Denied
Denials happen for legitimate reasons and also because of outdated records, mistaken identity, or data entry errors. You have 30 days from the denial to start an appeal with CBI.13Colorado Bureau of Investigation. Appeals Information The fastest route is CBI’s online appeal portal, though a paper form works too. CBI may ask you to submit a full set of inked fingerprints to compare 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. CBI can resolve the appeal faster when the problem is visible on the first look. If CBI upholds the denial, further legal options exist through the court system, and that conversation is worth having with an attorney who handles firearms law.
Stopping Repeat False Denials
If you have a common name or a record that keeps getting confused with someone else’s, the FBI’s Voluntary Appeal File can help. After a successful NICS appeal, you can apply for a Unique Personal Identification Number (UPIN). You put the UPIN on future Form 4473 submissions, and the background check system uses it to pull your verified identity directly.15Federal Bureau of Investigation. Voluntary Appeal File You submit a VAF application and a fingerprint card, electronically or by mail to the FBI CJIS Division. Processing takes a couple of months.
Penalties for Lying or Buying for Someone Else
Lying on Form 4473 is a serious offense at both levels. Under Colorado law, knowingly providing false information to acquire a firearm in a private transfer is a class 2 misdemeanor, and a conviction bars you from possessing firearms for two years.16Colorado Bureau of Investigation. C.R.S. 18-12-112 Federally, a false statement on Form 4473 can carry up to 10 years in prison, and federal prosecutors have been pursuing these cases more aggressively.17Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF). Federal Prosecutors Aggressively Pursuing Those Who Lie in Connection With Firearm Transactions A conviction also means a permanent loss of firearm rights.
Buying a firearm for someone who is prohibited is a straw purchase. The Bipartisan Safer Communities Act of 2022 created a standalone federal straw-purchase offense carrying up to 25 years in prison, with fines reaching twice the gross profits from the transaction.18Federal Register. Bipartisan Safer Communities Act Conforming Regulations