Douglas County, CO tax sales
How tax lien certificate and tax deed sales work in Douglas County, seat of Castle Rock: sale calendar, auction platform, over-the-counter lists, and the offices that run each sale.
Verified Jul 30, 2026 against official county and state sources.
New here? Read how Colorado tax sales work, the difference between a lien and a deed, and redemption periods.
How Douglas County sells delinquent taxes
Tax certificate sale (lien)
- Run by
- Douglas County Treasurer's Office
- Frequency
- annual
- Typical timing
- The county states: "Generally the tax sale is held in early November." It adds that "Tax sales are held once per year, typically in the fall, but must be held on or before the second Monday in December." The most recent sale the county lists is the 2025 Internet Tax Lien Sale, held Nov 6, 2025, at a 14% rate. The county had not posted a 2026 sale date at the time of review, and says information on an upcoming sale becomes available in October when the advertised property list is published.
- Next expected
- by the second Monday in December, 2026 (window; exact date posts closer to the sale)
Registration and deposit
Register online with SRI Inc. at zeusauction.com. The auction site opens for registration and research about three weeks before the sale. Bidders who have participated before must re-register annually. A US taxpayer ID is required, and banking information must be completed at registration because certificates, redemptions, refunds and IRS W-9 forms are prepared from that data. Bidders must accept the terms and conditions to participate. No deposit is required. Payment for winning bids is drawn by ACH from the bank account given at registration, and redemption payments are returned by ACH to the same account. Bidding opens 8:00 a.m. Mountain Time on the day of sale, and the day after the sale bidding closes hourly in batches of roughly 250 liens, with the first batch closing at 9:00 a.m. Questions about auction operation go to SRI at 1-800-800-9588.
Douglas County runs a premium-bid internet certificate sale. The minimum starting bid equals the delinquent tax, interest, advertising and fees shown on the auction site, and bidders may bid the amount up. The county warns that premiums are never returned and draw no interest, and should be treated as a cost of securing the lien. The redemption rate is set annually by the State Banking Commission at nine points above the federal discount rate as of Sept. 1, which produced 14% for the 2025 sale. If a property is wrongfully sold, the purchaser is paid two points above the discount rate with an 8% floor. Delinquent parcels must be advertised in a local paper for three consecutive weeks before the sale, with first publication at least four weeks out; the county advertises in Colorado Community Media newspapers and also posts the list on its website. Liens that do not sell are struck off to the county as county-held liens and can be bought afterward through the Treasurer's Office using its assignment request form. Lienholders may endorse later years' unpaid taxes onto the certificate if the owner has not paid current-year taxes by August 1. All sales are final, and the county states it will not represent the investor in any legal proceeding involving a lien. The county stresses a buyer-beware standard and says it cannot guarantee a parcel is buildable or desirable. Employees and officials of Douglas County, their immediate families and their agents may not buy liens at the sale. A separate process applies after three years: the county reports that the Treasurer's Deed process changed so deeds are no longer issued to the lienholder on request, and instead the deed option is sold at an online public auction to the highest bidder, with the lienholder able to redeem at the auction price to take ownership. Those deed auctions run on GovEase, which is a different platform from the certificate sale, so the two should not be confused. Deed applications cost $1,000 and are mailed to Douglas County Treasurer, Attn: Treasurer's Deed, PO Box 1208, Castle Rock, CO 80104. Older references use the douglas.co.us domain, which now redirects to douglasco.gov.
Register on SRI / ZEUSTax deed sale
- Run by
- County Treasurer
- Frequency
- on application
- Typical timing
- There is no fixed calendar. A public auction is scheduled only when a certificate holder applies for one, at least three years after the tax lien sale, and the treasurer must hold it between 110 and 125 calendar days after the known interested party notice is first published or mailed.
Registration and deposit
What sells is a certificate of option for treasurer's deed, not the parcel outright. The treasurer may only accept bids above the combined amount owed to the lawful holder plus the treasurer's fees and costs. County officials, county employees acting in their individual capacity, and their immediate family members may not bid. Payment is by cash, cashier's check, bank check, or electronic funds transfer subject to the treasurer's bidding rules. Any overbid goes to junior lienors who filed a notice of intent to redeem and then to the property owner. Confirm the notice, the bidding rules, and the auction venue with the county treasurer.
This Article 11.5 process replaced direct deed issuance on July 1, 2024. Colorado does not hold a routine calendar tax deed sale, so treat this as an occasional, application-driven auction rather than a recurring event.
Over-the-counter (leftover) purchases
Liens that draw no bid are struck off to the county and the treasurer issues the county a certificate of purchase. The county may then assign, sell, or transfer those certificates in the manner, at the times, and on the terms set by resolution of the board of county commissioners, which is how county-held liens are sold between annual auctions. A certificate on property owing more than ten thousand dollars in taxes needs the property tax administrator's approval after published notice. Whether a county maintains a published county-held list, and on what terms, varies. Contact the county treasurer.
New to this path? Read how over-the-counter certificates work.
County offices
Tax Collector (runs the certificate sale)
Notes for Douglas County
- Delinquency calendar from the county: statements go out in January, half payments are due the last day of February and June 15, full payment is due April 30, delinquent notices are mailed in July with interest accruing at 1% per month, and advertising plus the annual tax lien sale run across September through November.
- The county publishes machine-readable lien data, including a current-liens dataset on its ArcGIS open data hub and a downloadable file of advertised properties from the prior cycle, which is useful for pre-sale research before the new list is posted in October.
- Auction results are available online for at least five days after closing, and winning bidders are notified by email by SRI. The original certificate is retained in the Treasurer's Office, and assignments to another investor are handled by calling the office.
- The county notes that if a lienholder takes no action for 15 years the lien is cancelled.
Colorado statewide rules
- Redemption
- 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.
- Deed deposit
- The treasurer may require the applying lawful holder to post a deposit covering the recording fee plus the actual and reasonable cost of administering the auction, and all Article 11.5 fees and costs are chargeable as additional amounts owing under the tax lien. For bidders, the treasurer accepts cash, cashier's check, bank check, or electronic funds transfer subject to the treasurer's bidding rules. The statute sets no fixed bidder deposit percentage, so the deposit terms come from county bidding rules.
- Surplus proceeds
- Any overbid goes first to junior lienors in order of recording priority, measured as of the recording date of the application for public auction, who filed a notice of intent to redeem and whose liens are unredeemed, up to each lien's unpaid amount plus fees and costs. Whatever remains is paid to the property owner. The treasurer must post a public notice about these funds and mail the owner a notice within thirty calendar days of the auction. Unclaimed remaining overbids sit in escrow for six months without interest, then transfer to the state administrator under the Revised Uniform Unclaimed Property Act. An agreement to pay someone to recover an owner's overbid is unenforceable, and inducing one is a class 2 misdemeanor.
A tax deed does not convey marketable title. Most buyers file a quiet title action before they can resell or insure the property. See the due diligence guide.
Frequently asked questions
Does Douglas County, Colorado sell tax liens or tax deeds?
- Douglas County follows Colorado's tax lien state system.
When is the Douglas County tax certificate sale?
- The county states: "Generally the tax sale is held in early November." It adds that "Tax sales are held once per year, typically in the fall, but must be held on or before the second Monday in December." The most recent sale the county lists is the 2025 Internet Tax Lien Sale, held Nov 6, 2025, at a 14% rate. The county had not posted a 2026 sale date at the time of review, and says information on an upcoming sale becomes available in October when the advertised property list is published.. Registration and bidding happen on the county's online platform. Always confirm the exact date with the Tax Collector before the sale.
How often does Douglas County hold tax deed sales?
- on application. Each sale is scheduled and advertised in advance, so check the county's tax deed calendar for the next posted date.
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.
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