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Tax Sale Atlas

Arapahoe County, CO tax sales

Tax Sale Atlas maps the Arapahoe County, CO tax sale, one of 2,553 counties in 30 states. Colorado sells tax lien certificates paying up to 14%, redeemable for 3 years. Sale office, calendar and list locations read from the county’s own official pages on Jul 30, 2026.

How tax lien and tax deed sales work in Arapahoe County, seat of Littleton: sale calendar, auction platform, over-the-counter lists, and the offices that run each sale.

New to tax sales? Read how Colorado tax sales work or look terms up in the glossary.

Next sale
There is no fixed calendar.
Format
RealAuction
Registration
What sells is a certificate of option for treasurer's deed, not the parcel outright.
County office
303-795-4550
Every displayed fact carries a source badge. Verified Jul 30, 2026 against official county and state pages.How we verify
On this page

How Arapahoe County sells delinquent taxes

Tax certificate sale (lien)

RealAuction
Run by
Arapahoe County Treasurer's Office
Frequency
annual
Next expected
by the second Monday in December, 2026 (window; exact date posts closer to the sale)
Sale list
Tax Lien Sale Files (viewable sale list, county-held certificates, supplemental sale file)
When it runs
One annual online tax lien sale each fall, with bidding opening in early October and closing in early November. The Treasurer's tax lien sale page currently states: "The 2025 Tax Lien Sale will be held online on November 5th, 2026." The prior cycle ran on the same calendar: the published notice said "Pre-Bidding will commence at 8:00 AM MST on October 3, 2025. The auction will close in batches beginning at 8:00 AM MST on November 6, 2025." The county also says "The next online sale of Arapahoe County delinquent tax liens will open for deposits and bidding about a month in advance of the sale" and "The annual tax sale publication will be available in October."
Registration and deposit

Register on the auction site at https://arapahoe.coloradotaxsale.com, which the county says "is open for registration year-round." You submit name, address and similar details, and the site builds an IRS W-9 that is passed to the county. Registration itself costs nothing and requires no deposit, but returning buyers must re-register each year to keep their tax lien buyer number, and every number used by family members or business associates must be registered separately. Before bidding, fund a deposit equal to 10 percent of what you intend to spend, paid by ACH electronic check through the site's deposit wizard. Bidding is by premium: the auction awards each lien to the highest premium bidder at one dollar above the second highest bid, and liens close in batches at times posted on the auction site. Winning bidders pay the remaining balance by ACH or certified check no later than 4:00 p.m. MST on the payment deadline, or they forfeit the bid and the next highest bidder takes the lien. Unused deposits are returned about two weeks after the auction ends. Realauction posts training videos behind the Training link on the sale site, and the county links a practice sale site for new bidders.

Sale format and venue
The sale is conducted entirely online through Realauction; there is no live courthouse auction. Bidders without a computer can use two machines at the Treasurer's office at 5334 South Prince Street in Littleton, by appointment during office hours Monday through Friday 8:00 a.m. to 4:00 p.m., by calling 303-795-4550. Redemption interest is set by September 1 each year at nine points above the federal discount rate; the county published a rate of 14 percent for the 2025 sale, citing a 4.5 percent federal discount rate and Section 39-12-103, C.R.S. A real property lien must be three years old before the certificate holder can apply for a Treasurer's Deed; for mobile homes the lien must be held one year before applying for a Certificate of Ownership. Parcels carrying unpaid amortized special assessment installments have all future installments brought forward into the total lien amount. Delinquent tax payments must reach the Treasurer's office by end of day the day before the sale closes, and cleared funds are required for payments made after September 30. The Tax Lien Sale Files page also posts a county-held certificates report, the over-the-counter list of unsold certificates the county holds. Timing caution: the county's own page labels the sale "2025" while giving a November 5, 2026 date, and the 2025 published notice shows that sale closing in November 2025, so confirm the current year's exact open and close dates with the Treasurer's office or the auction site before planning deposits.
Register on RealAuction
Source: Arapahoe County Treasurer, Tax Lien Sale· Verified Jul 30, 2026

Tax deed sale

Run by
County Treasurer
Frequency
on application
Typical timing
There is no fixed calendar.
Registration
What sells is a certificate of option for treasurer's deed, not the parcel outright.
When it runs
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.

Sale format and venue
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.
Source: C.R.S. 39-11.5-102 - Application for public auctionC.R.S. 39-11.5-102· Verified Jul 29, 2026

Arapahoe County tax sale list and auction calendar

For Arapahoe County tax sale 2026 searches, use the county-run sources below rather than a copied parcel list, and confirm the parcel, registration cutoff, deposit, and payment deadline against the county before you bid. If the parcels on this list are vacant land rather than houses, what buying land at a tax sale hands you is the place to start.

  1. Get the advertised list

    Use Tax Lien Sale Files (viewable sale list, county-held certificates, supplemental sale file) for the current advertised parcels, then recheck it before the auction.
  2. Register to bid

    What sells is a certificate of option for treasurer's deed, not the parcel outright. Full requirements are in the sale card above.
  3. Sale day

    There is no fixed calendar. Bidding runs on RealAuction; check posted sale dates, registration status, and bidding windows there.
  4. Confirm with the office

    If the list, platform, and notice disagree, use County Treasurer as the source to confirm which parcels are actually offered.

Before you bid in Arapahoe County

  1. Start with the live sale list

    Pull the current advertised parcels from Tax Lien Sale Files (viewable sale list, county-held certificates, supplemental sale file). Lists can change before the sale, so recheck the county source before you price a parcel.
  2. Confirm 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.

  3. Check the state rules that change the bid

    Read the Colorado due-diligence checklist before bidding. Redemption, liens that survive a tax deed, title cleanup, and payment deadlines can change what a parcel is worth. Which liens survive is state law, so read what survives a tax deed in Colorado before you price the title work.
  4. Set a walk-away number

    Work out what the parcel is actually worth with the rural land value estimator, then turn it into a ceiling with the tax deed max-bid calculator.

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. Every state has its own name for what goes unsold, so check what Colorado calls its leftover tax-sale inventory.

Use the arrow keys to switch between these sections.

County offices

Tax Collector (runs the certificate sale)

Arapahoe County Treasurer's Office

303-795-4550

5334 S. Prince Street, Littleton, CO 80120

Official website

County notes

  • Michael R. Westerberg is the Arapahoe County Treasurer, listed on the department contact page and signing the published sale notice.
  • The county's Delinquent Tax Publications page carries the newspaper notices for real property, personal property and mobile homes; the 2025 real estate notice ran Thursday October 9, 16 and 23, 2025.
  • The Viewable File page is populated only in the weeks before the sale; the county states the viewable file "is available only up to three weeks before the tax lien sale begins," and it currently shows an older cycle's dated files.
  • The Supplemental Sale File page reports no supplemental file available at this time.
  • The Treasurer's office publishes a standing disclaimer that it cannot warrant anything about any lien sold, that liens may not be first or only liens, and that bidders must do their own due diligence.

Colorado rules

Max interest rate
14% per year, set by statute (bidding is on price)
Minimum return
No statutory minimum return; what you earn is set by the price at the sale
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.
Governing statute
C.R.S. Title 39, Article 11

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.

See the full Coloradorules and every county →

Frequently asked questions

Does Arapahoe County, Colorado sell tax liens or tax deeds?

Arapahoe County follows Colorado's tax lien state system.

When is the Arapahoe County tax certificate sale?

One annual online tax lien sale each fall, with bidding opening in early October and closing in early November. The Treasurer's tax lien sale page currently states: "The 2025 Tax Lien Sale will be held online on November 5th, 2026." The prior cycle ran on the same calendar: the published notice said "Pre-Bidding will commence at 8:00 AM MST on October 3, 2025. The auction will close in batches beginning at 8:00 AM MST on November 6, 2025." The county also says "The next online sale of Arapahoe County delinquent tax liens will open for deposits and bidding about a month in advance of the sale" and "The annual tax sale publication will be available in October." Registration and bidding happen on the county's online platform. Always confirm the exact date with the County Treasurer before the sale.

How often does Arapahoe County hold tax deed sales?

Arapahoe County holds its tax deed sale on application. There is no fixed calendar. Each sale is scheduled and advertised in advance, so check the county's tax deed calendar for the next posted date.

I own a property in this sale. Can I stop it?

Often yes, by paying the overdue taxes, interest, and costs before the deadline. Colorado's redemption rule: 3 years from the tax lien sale before the certificate holder can apply for the deed auction. Call the County Treasurer as early as possible for your exact payoff and options; deadlines are strict. Free help: lawhelp.org lists legal aid programs, and consumerfinance.gov lists HUD-approved housing counselors.

Where can I find the Arapahoe County tax sale list?

Arapahoe County posts its tax sale list at arapahoeco.gov. Lists go up ahead of each sale and keep changing until the sale date, so confirm every parcel against the county's legal advertisement before you bid.

Verified Jul 30, 2026 against official county and state sources.

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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Compare sale calendars, platforms, and rules across the state, or read the guides before you bid.

Call Arapahoe County Treasurer's OfficeOpen auction