The short answer
3 years from the tax lien sale before the certificate holder can apply for the deed auction
How the clock works
Redemption may be made at any time before a treasurer's deed is executed, so the practical window runs well past the three-year mark and through the Article 11.5 auction process. The treasurer must hold that public auction between 110 and 125 calendar days after the known interested party notice is first published or mailed, which gives owners and junior lienors a further defined period to pay. A separate rule lets an owner who was under a legal disability when the deed was executed redeem within nine years of the deed being recorded, at 15 percent per year plus the present value of any improvements.
Who can redeem
The owner, or the owner's agent, assignee, or attorney, any person holding a legal or equitable claim in the property, and the holder of a tax sale certificate. An undivided interest can be redeemed by paying a ratable share. Junior lienors do not redeem the property itself, but those who file a notice of intent to redeem have a claim on the auction overbid.
What the owner pays to redeem
The taxes, delinquent interest, and costs for which the lien was sold, plus redemption interest from the date of sale at the rate in force, plus every subsequent tax the holder paid and had endorsed on the certificate with interest at the same rate, plus the statutory fees the purchaser paid. Portions of months count as whole months. The premium the investor bid above the taxes is not part of the redemption amount and is not returned.
How your interest accrues
Redemption interest runs from the date of sale on the taxes, delinquent interest, and costs for which the lien sold, and on any subsequent taxes the holder pays and has endorsed on the certificate. Portions of a month count as a whole month. The rate is not fixed in the statute. C.R.S. 39-12-103(3) sets it at nine percentage points above the Kansas City Federal Reserve Bank discount rate, rounded to the nearest full percent, and the commissioner of banking establishes it each September 1 to take effect that October 1. The rate effective October 1, 2025 is 14 percent. There is no minimum-return floor in the redemption statute. The 8 percent floor investors sometimes see quoted sits in C.R.S. 39-12-111, which covers county repayment when a lien was wrongfully sold on land that owed no tax, and it does not apply to ordinary redemptions.
How the bidding works
Colorado does not bid the interest rate down. Every certificate sold in a given rate year earns the same statewide rate, and competition happens through premium bidding instead. The lien opens at the taxes, delinquent interest, and fees due, and the bidder who pays the largest amount in excess wins. That excess is credited to the county general fund. It earns no interest, it is not added to the redemption amount, and it is not refunded when the owner redeems, so an aggressive premium directly reduces the investor's yield. Treasurers may also set a minimum total below which they will not accept competitive bids.
What happens when it ends
At least three years from the date of the tax lien sale, the lawful holder of the certificate of purchase may file an application with the treasurer for a public auction of a certificate of option for treasurer's deed. This is not a conventional tax deed sale of the parcel. What sells is the option to take the treasurer's deed, and the treasurer delivers the deed to the winning purchaser on demand once the property remains unredeemed. On and after July 1, 2024 this Article 11.5 process is mandatory and a treasurer may no longer issue a deed under Article 11, which is how Colorado answered Tyler v. Hennepin County on owner equity.
A redeemed certificate, plus your accrued interest, is what makes the wait profitable; see how redemption periods work across states. An unredeemed certificate is instead your path to the property through a tax deed sale, which still does not convey marketable title on its own, so budget for a quiet title action.
Verified Jul 29, 2026 against Colorado statutes.
Tax Sale Atlas publishes educational information about public tax sale processes. This is not legal, financial, or investment advice. Rules, dates, and fees change; confirm with the county office before you bid.