The Park County tax lien sale is an annual December auction where the county treasurer sells liens on parcels with unpaid property taxes. Winning bidders don’t buy the property — they buy the right to be paid back, with interest, when the owner eventually settles up. If the owner never pays, the certificate holder can eventually apply for a deed to the property, but that path is longer, riskier, and more expensive than the marketing usually suggests.
Here is what the process actually looks like from a bidder’s side, and where the money can go wrong.
When the Sale Happens
Colorado law requires the auction to begin on or before the second Monday in December. Park County’s treasurer publishes the delinquent parcel list once a week for three consecutive weeks before the sale, showing the taxes owed, accrued interest, advertising charges, and other fees for each property.1Park County, CO. Tax Liens The first publication must appear at least four weeks before sale day, and the same notice is posted in the treasurer’s office.2FindLaw. Colorado Code 39-11-102 – Treasurer to Publish and Post Notice
Use that lead time. Pull records from the Park County Assessor’s Office, check the legal description, look at what the parcel actually is, and if you can, drive out and see it. The treasurer’s own guidance calls tax lien buying a “buyer beware” proposition and recommends visiting the property before you commit money.1Park County, CO. Tax Liens
Registering to Bid
You have to register before the auction. Colorado counties typically run the sale on an online platform where you set up an account with your name, mailing address, and taxpayer identification number. The name on your registration must match your tax ID exactly, because the certificate, any future redemption check, and every legal document are prepared from that information. Only bidders with a U.S. taxpayer ID may participate.
Registration also requires a completed IRS Form W-9, because the interest you earn is taxable and gets reported to the IRS. Some counties charge registration or auction fees. Confirm current requirements with the Park County Treasurer’s office at (719) 836-4334; the office is open Monday through Thursday, 7:00 a.m. to 6:00 p.m., and the mailing address is PO Box 638, Fairplay, CO 80440.
How Premium Bidding Works
Colorado uses a premium bidding system. The minimum bid on each lien equals the delinquent taxes, interest, and fees already owed. Bidders compete by offering to pay more than that minimum, and the highest offer wins.3Justia Law. Colorado Code 39-11-115 – To Whom Tax Lien Shall Be Sold Everything you offer above the minimum is the premium.
The premium is where new investors lose money. It earns no interest, and it is never refunded. When the owner redeems, you get back what you paid in taxes, interest, and fees, plus statutory interest on that base — but every dollar of premium is gone. The statute sends that excess to the county general fund.3Justia Law. Colorado Code 39-11-115 – To Whom Tax Lien Shall Be Sold Overbid a competitive parcel and your effective return can collapse to nearly zero. Set a ceiling per parcel before the auction opens, and stick to it.
If a lien draws no bids, the treasurer strikes it off to the county, which then holds the certificate. Those county-held certificates are handled separately from the public auction.
Paying and Receiving Your Certificate
Payment is due promptly once the auction closes. Park County accepts cash or certified funds only.1Park County, CO. Tax Liens No personal checks, no credit cards. Miss the payment window and you can forfeit the bid and be barred from future sales, so arrange funds before you start clicking.
When your payment clears, the treasurer issues a Tax Lien Sale Certificate. This is not a deed. It gives you no right to enter, occupy, or use the property. What it gives you is a priority financial claim: the owner has to pay you back through the treasurer before the title can be cleared.4City and County of Denver. Real Estate Delinquent Taxes and Tax Lien Sale Store the certificate somewhere secure. You will need it if you ever apply for a treasurer’s deed.
Endorsing Later Years’ Taxes
Buying the original lien often isn’t the last check you write. If the owner keeps missing tax payments, those new delinquencies pile up. Starting August 1 each year, existing certificate holders get the first option to pay the subsequent year’s unpaid taxes on the same parcel. That endorsement is added to your original certificate and earns the same interest rate the certificate already carries.
Two reasons this matters. It keeps another investor from buying a newer lien on your parcel and complicating your position. And when the owner finally redeems, you collect interest on every endorsed amount on top of your original investment. Skip the endorsement window and the county may put those new taxes into the next public sale, leaving a competing lienholder on the same property.
How Redemption Pays You Back
The owner can redeem at any time before the treasurer issues a deed. Redemption requires paying the delinquent taxes, interest, and costs from the original sale, plus redemption interest, plus any subsequent taxes you endorsed with interest on those. All of it goes to the treasurer, not to you directly.5Justia Law. Colorado Code 39-12-103 – Redemption Made – Interest
The redemption interest rate is set each year by Colorado’s Commissioner of Banking: nine percentage points above the discount rate the Federal Reserve Bank of Kansas City charges commercial banks on secured loans, rounded to the nearest whole percent. That rate locks in on September 1 and takes effect October 1, and it stays fixed for the life of your certificate.5Justia Law. Colorado Code 39-12-103 – Redemption Made – Interest Certificates issued in different years can carry different rates.
Once the treasurer receives a valid redemption payment, you get back your original purchase amount plus all accrued interest. The premium is not part of that reimbursement. Your actual return is the statutory interest on the base and any endorsements, minus the premium you paid to win the parcel.
Applying for a Treasurer’s Deed
If the property is still unredeemed three years after the original sale, the certificate holder can apply for a treasurer’s deed, which transfers ownership.6Justia Law. Colorado Code 39-11.5-102 – Application for Public Auction of Certificate of Option for Treasurers Deed Nothing about this is automatic. You file a formal application with the treasurer, pay a non-refundable application fee, and satisfy strict notification rules. The property owner, any mortgage holders, and other parties with a recorded interest must all receive proper notice before a deed can issue.
Those notice rules exist so people don’t lose their land without a real chance to pay up. Miss anyone, and the deed can be challenged in court later. Expect the process to take several months and involve costs beyond the application fee, including certified mailing and often legal counsel.
Watch the outer deadline: a tax lien certificate expires after 15 years. Hold one that long without applying for a deed and the lien is extinguished — you lose the investment and any claim to the property.7Justia Law. Colorado Code 39-11-148 – Tax Lien Certificate Limitations Most investors who intend to pursue a deed start soon after the three-year mark to leave room for complications.
Quiet Title After the Deed
Even after the treasurer executes the deed, you often can’t get title insurance or sell the property without filing a quiet title lawsuit. Treasurer’s deeds are treated as inherently risky because the whole chain depends on every procedural step in the sale and notification having been done correctly. Title companies routinely flag them as defective until a court confirms the new owner’s rights.
Colorado law specifically allows the grantee of a tax deed to file a quiet title action covering one or more parcels acquired at the sale.8Justia Law. Colorado Code 39-11-133 – Suit to Quiet Title or to Try Title The lawsuit asks a judge to declare that no one else has a valid ownership claim. Costs commonly run several thousand dollars in attorney fees and court costs, and it takes months. Anyone planning to take property through this route should build that expense into projections from the start.
Risks Worth Weighing Before You Bid
Tax lien investing gets marketed as a guaranteed return. The reality is more complicated. Park County’s own treasurer calls it a buyer-beware proposition.1Park County, CO. Tax Liens A few risks to think through before the auction:
- Worthless property. A lien can attach to a landlocked parcel, a contaminated lot, or a sliver of ground with no practical use. If no one redeems and you end up with a deed, you own whatever problems come with the land.
- Premium erosion. In competitive bidding, premiums can climb high enough to drop your effective return to single digits or lower. The premium never comes back.
- Bankruptcy stays. If the owner files bankruptcy, the automatic federal stay halts collection and freezes your path to a deed. A Chapter 13 filing can stretch the owner’s repayment over up to five years, freezing your investment for that whole time.
- Federal tax liens. Local property tax liens generally take priority over federal ones, but the interaction can create real complications at the deed stage if the IRS has a recorded lien.
- Quiet title costs. If you take the property, quiet title is essentially unavoidable when you eventually want to sell, finance, or insure it.
- Certificate expiration. Sitting on a certificate past 15 years extinguishes the lien entirely, and no treasurer’s deed can be issued after that.7Justia Law. Colorado Code 39-11-148 – Tax Lien Certificate Limitations
The most common mistake is treating every lien as interchangeable. A double-digit statutory return looks great on paper, but the return only exists if the owner redeems. When they don’t, you’re left deciding whether to spend more money chasing a deed on a property that may not be worth the trouble. Investors who do well at these sales research each parcel before bidding and walk away from anything they wouldn’t want to own.