Who this is for: Colorado residents who want to buy or sell a firearm privately and need a clear, accurate picture of the state’s background check, waiting period, and transfer laws before they list or answer an ad.
What you’ll learn:
- Colorado’s universal background check requirement and who’s exempt from it
- How the state’s 3-day waiting period actually works
- Magazine capacity, age, and red flag law basics that affect private transactions
- The step-by-step process for completing a legal private sale through an FFL
- Why an online marketplace built for Colorado gun owners can make the whole process safer and simpler
Selling a rifle to a neighbor or picking up a used handgun from someone you found online sounds simple enough. In Colorado, it isn’t quite a handshake-and-cash transaction anymore. Since 2013, private firearm sales in Colorado have been subject to a universal background check law, and more recent legislation has added a waiting period on top of that. If you’re planning to buy or sell a gun outside of a retail store, you need to understand exactly what the law requires — because getting it wrong isn’t a paperwork slip-up, it’s a criminal offense.
This guide walks through what private citizens actually need to know about private firearm sales in Colorado, from background checks to magazine limits, and explains why more sellers are turning to purpose-built platforms instead of generic classifieds to get it done right.
Understanding Colorado’s Private Firearm Sale Laws
Colorado is one of the roughly twenty states that require a background check on nearly every private firearm transfer, not just sales made through a licensed dealer. This came out of House Bill 1229, passed in 2013 after the Aurora theater shooting, and it fundamentally changed how private sales work in the state.
The Universal Background Check Requirement
Under Colorado law, if you want to sell, trade, or even give away a firearm to someone who isn’t an immediate family member, that transfer has to run through a federally licensed firearms dealer (FFL). The dealer conducts a background check through the Colorado Bureau of Investigation, essentially the same process as buying a gun new from a store. There’s no way around this for a stranger-to-stranger sale — meeting in a parking lot and exchanging cash for a pistol without a background check is a misdemeanor on the first offense, and it escalates from there.
The dealer will typically charge a small fee, often somewhere between $10 and $25, to run the check and handle the paperwork. Buyer and seller usually agree ahead of time on who covers that cost.
Family Transfer Exemptions
Colorado does carve out an exception for immediate family. You can transfer a firearm without a background check to a spouse, civil union partner, parent, grandparent, sibling, child, or grandchild. That’s it — the exemption doesn’t extend to cousins, in-laws, or close friends, no matter how long you’ve known them. There’s also a narrow exemption for temporary transfers at a shooting range, during hunting, or in an emergency situation involving self-defense.
The 3-Day Waiting Period
Colorado added a new wrinkle to gun purchases with a mandatory waiting period, which took effect in 2024. Once a buyer clears the background check, there’s a minimum three-business-day hold before they can actually take possession of the firearm. This applies to sales handled through dealers, which by extension includes private sales that route through an FFL for the required check. If you’re selling privately and expecting a same-day handoff, plan around this — it doesn’t happen anymore in most cases.
Other Colorado Gun Laws Private Sellers Should Know
The background check and waiting period get the most attention, but there are a handful of other rules that affect what you can legally sell and to whom.
Magazine Capacity Restrictions
Colorado has capped magazine capacity at 15 rounds since 2013. Magazines manufactured or acquired before the ban took effect can still be legally owned, but selling or transferring a magazine that holds more than 15 rounds to another Colorado resident isn’t allowed. If you’re clearing out an old collection that includes higher-capacity magazines, check the manufacture date and be upfront with buyers about what’s included in a sale.
Age Requirements
Federal law already sets minimum ages of 18 for long guns and 21 for handguns when buying from a licensed dealer. Colorado raised the bar further with Senate Bill 23-169, which generally requires buyers under 21 to complete a hunter education course before purchasing any firearm through a dealer — a rule that applies to the FFL portion of a private sale background check as well. It’s worth confirming a buyer’s age and eligibility before you even start the process, especially if you’re selling to someone you don’t know well.
Prohibited Purchasers and Red Flag Laws
Colorado’s Extreme Risk Protection Order law, commonly called the red flag law, allows courts to temporarily remove firearms from someone deemed a danger to themselves or others. As a private seller, you won’t necessarily know if a buyer is subject to an ERPO — which is exactly why the background check step matters so much. It’s the mechanism that catches prohibited purchasers, whether they’re barred due to a felony conviction, domestic violence restraining order, or an active protection order. Skipping the check because you “trust the guy” isn’t just risky, it’s the entire point of the law you’d be violating.
How a Private Firearm Sale Actually Works in Colorado
Here’s what the process looks like in practice, start to finish:
- Seller and buyer agree on the firearm, price, and terms, typically after connecting through a classifieds site, gun show, or word of mouth.
- Both parties bring the firearm to a licensed FFL dealer. Some dealers require an appointment; others accept walk-ins for transfers.
- The dealer initiates a background check on the buyer through the Colorado Bureau of Investigation’s system.
- Assuming the buyer clears the check, the mandatory waiting period begins — currently a minimum of three business days.
- Once the waiting period ends, the buyer returns to the dealer, completes any remaining paperwork, and takes possession of the firearm.
- The seller receives payment, and the dealer keeps a transfer record as required by law.
It’s a longer process than it used to be, no question. But it’s also the only legal path for a private sale between people who aren’t immediate family, and skipping steps isn’t worth the risk of a felony charge.
Why Use an Online Marketplace Like 2A Marketplace
General classifieds sites weren’t built with firearm transfers in mind. They don’t verify who’s on the other end of a message, they don’t connect you with a nearby FFL, and they definitely don’t walk you through Colorado’s specific requirements. That gap is exactly the problem a dedicated platform like 2A Marketplace is designed to solve.
Finding Verified Buyers and Sellers
Anonymous classifieds ads are a magnet for scammers, lowball offers, and buyers who ghost after agreeing to a price. A marketplace built specifically for firearm transactions can incorporate account verification and seller ratings, so you’re not negotiating blind with a stranger who has zero track record. Browsing current firearm listings gives you a much clearer sense of who you’re dealing with before money changes hands.
Connecting with Local FFLs for Compliant Transfers
Since every non-family private sale in Colorado has to route through a licensed dealer anyway, having a built-in way to locate one nearby saves a genuine headache. Instead of cold-calling gun shops to ask about transfer fees and availability, a resource like a local FFL transfer directory puts that information in one place, which speeds up the whole process for both sides of the deal.
Avoiding Common Private Sale Pitfalls
A lot of private sales go sideways over things that have nothing to do with the firearm itself — mismatched expectations about who pays the transfer fee, confusion over the waiting period, or a buyer who didn’t realize a background check was even required. A platform that’s specifically oriented toward Colorado firearm transactions can bake that education right into the listing and messaging process, cutting down on the back-and-forth and the surprises. Resources like a state-specific compliance guide also help both parties understand what’s required before they ever meet up.
None of this replaces the legal requirement to complete the transfer through an FFL. What it does is remove a lot of the guesswork and risk that comes with meeting a stranger off a random classifieds post, while making sure everyone involved actually understands the rules they’re operating under.
Key Takeaways
- Nearly all private firearm sales in Colorado require a background check run through a licensed FFL dealer, with narrow exceptions for immediate family transfers.
- A mandatory 3-day waiting period applies after a buyer clears the background check, so plan for a multi-day process rather than a same-day handoff.
- Magazines over 15 rounds, sales to buyers under 21, and transfers to prohibited persons all carry specific legal restrictions private sellers need to respect.
- Skipping a required background check is a criminal offense in Colorado, not a technicality — there’s no legal shortcut for a stranger-to-stranger sale.
- Platforms built specifically for firearm transactions, like 2A Marketplace, help connect verified buyers and sellers and point them toward local FFLs, making legal compliance far more straightforward than generic classifieds.
Frequently Asked Questions About Private Firearm Sales in Colorado
Do I need a background check to sell a gun to my brother in Colorado?
No. Colorado’s immediate family exemption covers spouses, civil union partners, parents, grandparents, siblings, children, and grandchildren. A sale or gift to your brother doesn’t require a background check, but it’s still smart to document the transfer with a bill of sale for your own records.
How long does the Colorado waiting period actually take?
The law requires a minimum of three business days between a cleared background check and the buyer taking possession of the firearm. Weekends and holidays can extend that timeline slightly depending on when the check is initiated, so it’s rarely a same-day process anymore.
Can I sell a firearm to someone from out of state?
Handguns generally cannot be sold directly across state lines to a private buyer — federal law requires that transfer to go through an FFL in the buyer’s home state. Long guns have slightly more flexibility but still typically need to pass through a licensed dealer for interstate transfers, so it’s worth confirming the specifics with an FFL before agreeing to a sale.
What happens if I sell a gun privately without a background check?
You’d be violating Colorado’s universal background check law, which carries misdemeanor penalties for a first offense and can escalate to a felony for repeat violations. It’s not a risk worth taking, especially since the process of using an FFL for the check is straightforward and widely available across the state.
Is 2A Marketplace a replacement for going through an FFL?
No — Colorado law still requires most private sales to be processed through a licensed dealer for the background check. What a platform like 2A Marketplace offers is a safer way to find legitimate buyers and sellers and locate a nearby FFL to handle that required step, not a way around it.