Colorado Commercial Property Tax Appeals
Protest to the county assessor by June 1. Notices of Valuation mail about May 1, and SB26-046 moves the protest deadline from June 8 to June 1 starting with the 2027 cycle. If the assessor denies the protest, appeal to the County Board of Equalization by July 15 in most counties, or September 15 in the nine large counties on the alternate procedure, and from there to the Board of Assessment Appeals, district court, or arbitration by September 1 (December 1 in alternate-procedure counties), or 30 days after the decision if it was mailed off the regular schedule (SB26-046, effective August 12, 2026). Colorado revalues in odd years, so a reduction won in 2027 normally holds for 2028 as well, and a missed window can still be reached by abatement petition for up to two prior years.
Your calendar from today
It is September 2026. The 2026 protest window closed June 8, and the next Notices of Valuation do not mail until May 1, 2027. Here is what is still reachable for a Colorado commercial owner who has never filed, and what to do with the months in between.
- Tax year 2024An abatement petition under § 39-10-114, C.R.S. must be filed within two years after January 1 of the year following the levy; for 2024 taxes that is January 1, 2027. After that date the year is closed for good.
- Tax years 2025 and 2026Both rest on the 2025 revaluation and its June 30, 2024 level of value. If you never protested, overvaluation abatement is open for both (2025 until January 1, 2028, and 2026 after the December levy, until January 1, 2029), but the evidence has to prove value as of June 30, 2024, not today's market. If you did protest 2025 and received a Notice of Determination, the statute bars an overvaluation abatement for that year.
- September 15, 2026Protested in June and denied in August? In the nine alternate-procedure counties the County Board of Equalization deadline for 2026 is September 15, and that window is still open as this is written.
- Now through DecemberThe June 30, 2026 level-of-value date has already passed, so everything that will decide your 2027 value exists today: sales through mid-2026, your 2025 and first-half-2026 rent roll and operating statements, and the building's condition heading into January 1, 2027. This is when I build the file: before the notice, not after.
- April 15, 2027Business personal property declaration (DS 056) due, if your equipment exceeds the $58,000 exemption that applies from 2027. Real property files nothing before the notice.
- May 1 – June 1, 2027Notices of Valuation mail about May 1. Protest to the assessor by June 1, 2027. The assessor-level protest is free and compels no income disclosure.
To know now whether your building is a candidate, the Free Assessment Review is written and signed, and acknowledged within one business day. The abatement fine print, including the protest-and-determination bar, is in the calendar below.
One Appeal Can Pay Twice
Colorado runs on a two-year assessment cycle: county assessors revalue every odd-numbered year, and even years generally carry that value forward. Win a reduction in a revaluation year and it typically holds for both years of the cycle, making a Colorado appeal one of the highest-leverage tax decisions a commercial owner makes.
The other thing owners miss: values are set as of a statutory "level of value" date, June 30 of the year before the revaluation. Your 2027 assessment won't reflect the market in 2027; it will reflect June 30, 2026. In a market where office and retail values have moved sharply, the gap between the statutory date and the assessor's mass-appraisal model is exactly where appeals are won.
Commercial owners also carry an outsized share of the load. For 2026, commercial-classed property (offices, retail, lodging, warehouse) is assessed at 25% of market value, while industrial-classed property, vacant land, and business personal property are assessed at 26%, and residential property at just 6.8% for local-government levies and 7.05% for school levies (the local-government rate applies after a statutory adjustment to actual value). The legislature has adjusted these ratios almost every year since 2021, and every dollar of overstated market value flows through them and your district's mill levy straight to the tax bill.
Two rules that change the psychology
Unlike most states, Colorado gives the county's number no presumption of correctness: TABOR stripped it, and the assessor must "consider and document" all applicable approaches to value before the number is set (§ 39-1-103(5)(a), C.R.S.). The assessor's own manual instructs staff to build a defense file, because in Colorado the value must be proven, not presumed.
Escalation risk is also capped by statute: past the CBOE, the value cannot be adjusted more than 5% above the CBOE's figure (§ 39-8-108(5)(a.5), C.R.S.). The fear that keeps owners from appealing has a ceiling written into law.
Every Date That Matters
Colorado's appeal ladder is strictly sequential: miss a rung and you generally wait for the next cycle (or fall back to abatement). Here is the full calendar for a revaluation year.
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January 1Assessment dateThe property is assessed based on its status and condition on January 1, at market value as of the prior June 30 level-of-value date.
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~May 1Notices of Valuation mailedAssessors mail NOVs for real property. This starts the clock. Review it immediately; from 2027 the protest window is barely four weeks.
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June 1Assessor protest deadlineDeadline to protest the value with the county assessor, moved up from June 8 by SB26-046 (2026), effective with the 2027 cycle. This first level is where well-documented cases often resolve fastest, and where thin filings get rubber-stamped denials.
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Late June – AugustAssessor decisionsAssessors mail Notices of Determination by the end of June in most counties, and by August 15 under the alternate protest and appeal procedure of § 39-5-122.7, C.R.S., which is required in reappraisal years for the nine counties over 300,000 population (Denver, Adams, Arapahoe, Jefferson, Douglas, Boulder, El Paso, Larimer, and Weld), and open to any other county that elects it for the year by May 1.
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July 15County Board of Equalization appealDeadline to appeal the assessor's determination to the CBOE in regular-procedure counties (alternate-procedure counties run to September 15). CBOE is an evidentiary hearing, and filing one triggers mandatory income-and-expense disclosure for income-producing property, due by a hard July 15 deadline in alternate-procedure counties, months before the hearing. Go in with the valuation case already built.
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Sept 1 (Dec 1 in alternate-procedure counties) or +30 days if notified off-scheduleBAA, district court, or arbitrationThree escalation venues, one deadline: the later of September 1, December 1 in alternate-procedure counties, or 30 days after the decision if it was mailed off the regular schedule (SB26-046, effective August 12, 2026). The state Board of Assessment Appeals is the workhorse for commercial cases; district court and binding arbitration fit specific fact patterns. Venue choice is strategy, not paperwork.
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Up to 2 years backAbatement & refund petitionsMissed the protest window? Colorado's abatement process allows petitions on taxes levied erroneously or illegally for up to two prior years, the main remedy once the annual calendar has closed.
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January 1Assessment date, and the exemption linePersonal property is listed wherever it sits at noon January 1, then trended to the same June 30 level of value as real property. At or below the threshold ($56,000 per county through 2026, a flat $58,000 from 2027 under SB26-116), nothing is taxed and no filing is due.
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April 15Declaration Schedule (DS 056) dueBusinesses above the threshold file the DS 056 with each county assessor by April 15. Extensions of 10 or 20 days are available by written request ($2 per day). The late penalty is the lesser of $50 or 15% of the tax, but stonewalling after two requests can add up to 25% of assessed value. Whether a filed schedule is right is a separate question: see the free declaration review.
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June 15Notices of Valuation mailed (July 15 from 2027 in alternate-procedure counties)Personal property NOVs mail by June 15, six weeks behind the real property notices, with the protest window already running. From 2027, in counties using the alternate protest procedure (the nine over 300,000 in a reappraisal year), they mail by July 15.
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June 30Assessor protest deadline (July 31 from 2027 in alternate-procedure counties)Postmarked or delivered by June 30 (July 31 from 2027 in alternate-procedure counties): a later deadline than real property’s, but a tighter one, as little as fifteen days from the notice. Hearings conclude by June 30 (July 31 in alternate-procedure counties from 2027); written determinations mail by July 10 (August 15 in alternate-procedure counties).
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July 20County Board of Equalization appealFive days after real property’s July 15 deadline, an easy transposition error. Alternate-procedure counties move both rolls to September 15. From the CBOE decision, the same deadline to the BAA, district court, or arbitration applies: the later of September 1, December 1 in alternate-procedure counties, or 30 days after a decision mailed off the regular schedule.
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Up to 2 years backAbatement & refund, with personal-property fine printErroneous or illegal personal property levies can be abated by petition within two years after January 1 of the year following the levy, and “clerical error” expressly includes the taxpayer’s own mistakes on the declaration schedule (though refunds of that kind accrue no interest). Two limits apply. Once a protest drew a Notice of Determination, overvaluation abatement is barred unless the protest was withdrawn and the assessor’s own audit shows a reduction is warranted, and a non-filer valued on best information available who skips the June protest can’t relitigate through abatement (Production Geophysical, 860 P.2d 514). Denials appeal to the BAA within 30 days.
Counties on the alternate protest and appeal procedure (the nine over 300,000 population in reappraisal years, and any county that elects it for the year) extend several dates. Always confirm the current year's dates on your NOV; I track every county's calendar so you don't have to. Personal property: declarations C.R.S. § 39-5-116; notices and protests §§ 39-5-121–122; CBOE § 39-8-106; abatement §§ 39-10-114, 39-10-114.5; exemption § 39-3-119.5 ($56,000 per ARL Vol. 5; SB26-116 enrolled text for 2027).
Market Value × Assessment Rate × Mill Levy
Three numbers set every Colorado commercial tax bill. The assessor's market (actual) value: the number you can appeal. The assessment rate: 25% for commercial classes and 26% for industrial classes, vacant land, and personal property in 2026, set by the legislature. The mill levy: the sum of every overlapping district's school and non-school levies, which in metro Denver commonly runs from about 70 to more than 120 mills depending on the district.
Only the first number is on trial in an appeal, but the other two are why it's worth trying: at 100 mills, every $1,000,000 of overstated market value costs $25,000 per year at the 25% commercial rate ($26,000 at the 26% industrial rate) and roughly $50,000 across a two-year cycle.
Mill levies vary block by block. Parts of Adams County exceed 120 mills while some Denver districts sit near 75, meaning two identical buildings a few miles apart can face effective tax rates anywhere from roughly 2% to over 3% of market value. Knowing your district's levy is step one of any savings estimate.
| Market Value | Assessed (25%) | Tax at 80 mills | Tax at 100 mills | Tax at 122 mills |
|---|---|---|---|---|
| $2,000,000 | $500,000 | $40,000 | $50,000 | $61,000 |
| $5,000,000 | $1,250,000 | $100,000 | $125,000 | $152,500 |
| $10,000,000 | $2,500,000 | $200,000 | $250,000 | $305,000 |
| $25,000,000 | $6,250,000 | $500,000 | $625,000 | $762,500 |
Annual tax = market value × assessment rate × mill levy ÷ 1,000, shown at the 25% rate that applies to commercial-classed property (offices, retail, lodging, warehouse) for 2026; industrial-classed property, vacant land, and business personal property assess at 26%. Mill levies shown span the typical metro-Denver commercial range; the 122-mill column reflects levels seen in parts of Adams County. A 10% value reduction on the $10M row at 100 mills saves $25,000 per year.
The Grounds That Actually Move Values
Assessors value tens of thousands of properties with mass-appraisal models. Models miss things. A commercial appeal succeeds by replacing the model's assumptions with the property's reality:
Market evidence at the statutory date
Comparable sales and market conditions as of the June 30 level-of-value date, not today's market and not the assessor's time-trended approximation of it.
Actual income & expenses
The assessor's pro forma assumes stabilized occupancy and market rents. Actual rent rolls, concessions, vacancy, and expense loads frequently tell a lower-value story.
Obsolescence the model can't see
Functional layouts the market has moved past, deferred capital needs, and economic obsolescence; the office era gap is the obvious current example.
Data & classification errors
Overstated square footage, wrong property class or abstract code, misallocated land value, and double-counted components between real and personal property.
The disclosure trade-off
Appealing to the CBOE triggers mandatory income-and-expense disclosure for income-producing property, due by July 15 in the big alternate-procedure counties. Two things to know. First, the data becomes part of the record, so decide what story it tells before you escalate. Second, only data pre-dating the June 30 appraisal date may be used to support the county's value; post-appraisal leases and rent bumps are off-limits. Whether the reduction is worth that disclosure is the question should you appeal your Colorado commercial assessment works through.
Cycle timing
Values set in 2027 will rest on June 30, 2026 market data. Positioning the record now (sales, income, condition) is how sophisticated owners walk into May 2027 ready.
Office: Where the Model and the Rent Roll Disagree
Every 2027 office value in Colorado will rest on conditions as of June 30, 2026. The assessor's mass-appraisal model gets there with a stabilized vacancy allowance, a market rent by class, a typical expense ratio, and a capitalization rate applied across the class, and in no property type are those four assumptions further from the individual building than in office. The appeal is the record of where they diverge. Nothing below is a statistic; each is a line of evidence I build from the building's own documents and from the sales and leases that closed before the level-of-value date.
Vacancy and concessions at the level-of-value date
Physical vacancy is the easy number. The model's blind spot is economic vacancy: free rent, tenant-improvement allowances, leasing commissions, and the gap between the face rent on a lease and the effective rent after the concessions it took to sign it. The evidence is the rent roll as of June 30, 2026 and the deals that closed in the twelve months before it, with their full economics, not the headline rate. The post-appraisal bar cuts both ways: a lease signed after June 30, 2026 cannot support the county's value, and it cannot support yours either.
Level of value: § 39-1-104(10.2), C.R.S. (June 30 of the year preceding the reassessment year).Flight to quality
The office market has split: newer, amenitized buildings leasing against commodity Class B and C product that competes on price and often loses anyway. A class-wide rent and cap rate averages the two halves and lands on neither. The comparable set for a B building is B sales and B leases matched by vintage, floor plate, parking, and lease-up profile. Where the trades that did close carried unusual terms, those terms are part of the market evidence, not a reason to discard the sale.
Sublease overhang
Space that is leased but sitting on the sublease market is income on the rent roll and supply in the market at the same time. The model counts it as occupied. A buyer counts it as rollover risk priced below the direct rent, and the asking rents on sublease listings around the level-of-value date are direct evidence of what the market would pay for the building's space. Document the listings, the asking rents, and the term remaining; they are as much a part of the June 30, 2026 picture as the sales.
Capital needs and repositioning
Deferred mechanical, elevator, and life-safety work, the cost of spec suites to lease a floor, and (where the highest and best use has moved) the cost to reposition or convert the building are deductions from value, not upside. The model sees none of them. A capital-needs assessment dated near the level-of-value date, with the engineer's numbers rather than the owner's, is the difference between an obsolescence argument and an obsolescence claim.
Managing the CBOE disclosure
The assessor-level protest is free and compels no disclosure; a well-documented office case often resolves there. Appealing to the County Board of Equalization compels income-and-expense disclosure for income-producing property (due by July 15 in the alternate-procedure counties), and the disclosure becomes part of the record. Two rules decide how I handle it. First, the story is settled before the escalation, not after: the actual vacancy, the concessions, the sublease listings, and the capital needs are assembled so that what is disclosed is the case, not a liability. Second, only data pre-dating June 30, 2026 may support the county's value, so the record is organized around that date, with post-appraisal leasing kept out of both sides' evidence.
If the disclosure would reveal more than the reduction is worth (a tenant's confidential terms, a refinancing in progress), that is a reason to stop at the assessor level, and I say so in writing before anything is filed. The decision framework is on should you appeal your Colorado commercial assessment.
Hotels: Where Colorado Appeals Get Technical
No property type turns on valuation methodology like a hotel. The revenue mixes lodging, food and beverage, spa, retail, and services, and the assessment turns on what portion of that income belongs to the real estate, and what portion of the operation is even "lodging" at all. Two levers decide most Colorado hospitality appeals, and both rest on authority the assessor cannot ignore: county assessors are statutorily required to follow the state's Assessors' Reference Library (§ 39-2-109(1)(e), C.R.S.), and the Colorado Supreme Court has confirmed the manuals bind them.
The Rushmore rule
Colorado's tribunals have settled how hotel intangibles come out of the income approach: the Rushmore method (deducting management and franchise fees and returns on FF&E), and not the broader business-enterprise carve-outs taxpayers have pushed. In the Gaylord Rockies litigation, the Board of Assessment Appeals found the Rushmore method "most closely aligns with what occurs in the actual market for hotels"; the Court of Appeals affirmed, and the Supreme Court declined review. The practical consequence is that you don't fight the method; you win inside it. Market-level management and franchise fees, defensible FF&E treatment, and clean income attribution are where the dollars move.
Aurora Convention Ctr. Hotel, LLC v. Adams Cty. Bd. of Equalization, BAA Dkt. 78792 (2021), aff'd, Colo. App. No. 21CA0508 (2022), cert. denied (Colo. 2023).Income that isn't the hotel's
The flip side of Rushmore discipline is attribution: income that doesn't belong to the parcel doesn't belong in the value. The Colorado Supreme Court has held that rental-program income from separately owned condominium units could not be swept into a lodge's valuation, and the same principle reaches revenue booked through the hotel but earned elsewhere: off-site food-and-beverage operations, third-party leases, off-parcel services. My largest hotel result came from exactly this analysis: dissecting the income statement and touring the operation to show a significant share of F&B was handled off-site.
Lodge Properties, Inc. v. Eagle Cty. Bd. of Equalization, 2022 CO 9.The 30-day reclassification
The assessor's own manual classifies hotel rooms leased or rented for thirty consecutive days or longer by the same person or business entity as residential use, and prescribes a mixed-use allocation by extended-stay revenue or room-nights. Corporate housing, crew contracts, relocation blocks, and travel-nurse programs all count. Every point of value reclassified is assessed at roughly 6.8–7.05% instead of the 25% lodging rate, a cut of nearly three-quarters on that slice. The documentation (folios, leases, revenue splits) is the case.
ARL Vol. 2, Ch. 6 & Vol. 3, Ch. 7 (Mar. 2026 ed.); §§ 39-1-104(1.6)(a), 39-1-103(9), C.R.S.The condo-hotel four-unit rule
Condominium, townhome, and timeshare units rented nightly are still classified residential, not lodging, unless a single owner or related-persons group holds more than four unit-equivalents in the project and operates them as a lodging business. Participation in a common rental-management program doesn't flip them; the test is ownership concentration, not rental activity. In resort counties, that's the difference between the ~6.8–7.05% residential ratio and the 25% lodging rate, per unit, every year. Assessors sometimes reclassify rental-program units wholesale anyway.
§ 39-1-102(5.5)(a)–(c), C.R.S.; ARL Vol. 3, Ch. 7 & Vol. 2, Ch. 6 ("hotel units" criteria).What the 30-day rule is worth
A $40M full-service hotel where extended-stay business (corporate housing, crew contracts, 30-day-plus bookings) represents 20% of room revenue. Under the ARL's revenue-analysis allocation, that share of value is classified residential and assessed at the residential ratio instead of the 25% lodging rate.
Rushmore, worked
A full-service hotel with $20M of total revenue and $5.6M of income before management, franchise, and FF&E deductions. Rushmore takes the business and the furniture out of the real estate in four lines, each argued at market from the hotel's own agreements, and capitalizes what is left. The fight is rarely over the method; it is over the levels: whether the franchise fee is deducted at all, whether the reserve is 3% or 4%, whether the FF&E earns a return as well as a reserve. Each line is worth real money: at an 8% capitalization rate, every $100,000 of income properly deducted removes $1.25M of value, or $31,250 a year of tax at the 25% rate and 100 mills.
PIPs and renovation obsolescence
A brand-mandated Property Improvement Plan is a liability the market prices before it prices anything else: a buyer deducts the PIP cost from what it will pay, and a hotel that has deferred one carries that deduction whether or not the assessor's model sees it. The scope letter, the cost estimate, and the deadline in the franchise agreement are the evidence, and they belong in the record as physical and functional obsolescence, not as a footnote.
Renovation years cut the other way. Rooms out of order, displaced group business, and the ramp back to stabilized occupancy all sit in the income that pre-dates the June 30 level-of-value date (the only income either side may use), and the cost approach should not credit the renovation as value the income has not yet earned. Timing matters twice: condition on January 1 sets what is assessed, and the market as of June 30 of the prior year sets the number.
Authority: assessors must follow the ARL (§ 39-2-109(1)(e), C.R.S.; Huddleston v. Grand Cty. Bd. of Equalization, 913 P.2d 15 (Colo. 1996)). The 30-day illustration applies the 6.8% residential rate for local-government levies across the whole 100 mills; the school-levy share of a bill assesses the residential slice at 7.05%, so the actual saving runs slightly below the figure shown. The residential portion must be valued by the market approach with documentation supporting the allocation. The Rushmore figures are assumptions chosen to show the mechanics; every input is argued at market from the hotel's own agreements. Board and trial-court outcomes are case-specific; the Gaylord valuation dispute has continued for later tax years.
Winning on Both Sides of the Line
Data centers, manufacturers, energy and process facilities, and equipment-heavy operators pay property tax on two rolls at once, the real property and the business personal property schedule, and the line between them decides the bill. Colorado's rules for that line, and for what never belongs on either roll, are unusually taxpayer-friendly for owners who know them.
The first-use exemption
Business personal property is exempt until it is first used in the business, and the manual reads that generously: equipment on site but not in service qualifies, and so does equipment in test or "shakedown" mode on January 1. Because Colorado bars proration, status on the assessment date controls the entire year: a commissioning tranche that goes live January 2 instead of December 30 is tax-free for a full year. The burden of proving first use is the taxpayer's: paper the commissioning logs, acceptance tests, and go-live dates.
§ 39-3-118.5, C.R.S.; ARL Vol. 5, Ch. 2 ("Business Personal Property Not as Yet in Use").The Del Mesa fixture test
Classification turns on function, not attachment: an item bolted, hard-piped, or wired into the building is still personal property if its use is primarily tied to the business operation rather than the building. Supplemental cooling, power distribution, and process infrastructure belong on the personal side, where the depreciation tables, obsolescence deductions, and first-use exemption live. Run the audit both directions: base-building systems sitting on the personal schedule are being taxed twice.
Del Mesa Farms v. Montrose Cty. Bd. of Equalization, 956 P.2d 661 (Colo. App. 1998); § 39-1-102(4), C.R.S.; ARL Vol. 5, Ch. 2.The software carve-out
Software is exempt intangible property in Colorado: application programs, operating systems, custom code, even software controlling production equipment. The only exception is the boot firmware that makes hardware run. Most owners declare full invoice cost on servers, POS, and phone systems and silently pay tax on bundled licenses for the asset's whole life. Scrub the ledger; carve the software out of every declared cost.
§ 39-3-118, C.R.S.; ARL Vol. 5, Ch. 7 ("Software").Technology tables & market guides
The state's own tables treat tech gear kindly: computers and servers get no cost trending, three-to-four-year lives, and a 7% residual, and published used-computer market guides may be substituted when they're lower still. The common county error is coding servers into a general 8–12 year equipment category, which can overvalue a deployment severalfold. Auditing the asset coding is often the whole appeal.
ARL Vol. 5, Chs. 4 & 7 (Technologically Advanced Personal Property tables; market-guide substitution).The cost-approach ceiling
File the declaration on time with complete cost detail and the cost approach becomes a legal maximum on your equipment's value; the market and income approaches may only be used to go lower. An assessor who wrongly denies a compliant taxpayer the cost approach owes the taxpayer's protest costs. Skip the filing and the cap is gone, and a bloated "best information available" value generally can't be fixed by abatement later.
§ 39-1-103(13)(a), (c), C.R.S.; ARL Vol. 5, Ch. 3; Prop. Tax Adm'r v. Production Geophysical, 860 P.2d 514 (Colo. 1993).Consumables & small assets
Anything with an economic life of one year or less (at any cost) and anything with a fully loaded installed cost of $350 or under is exempt "consumable" property. Fixed-asset ledgers are full of small tools, peripherals, and smallwares dutifully declared and taxed forever. An annual scrub takes them off the schedule, item by item, at the assembled-unit level.
§ 39-3-119, C.R.S.; ARL Vol. 2, Ch. 3 & Vol. 5, Ch. 2 ("Exemption of Consumable Personal Property").The January 1 playbook
A data center commissioning a $30M equipment tranche over year-end. On January 1 the servers are racked but still in acceptance testing, "shakedown mode" under the assessor's manual. The entire tranche is exempt for the year; it first becomes taxable the following January 1.
Illustration assumes an effective personal-property burden of roughly 2.5–3% of value at metro mill levies; exact results depend on the county, levy, and documentation. First-use, classification, and exemption positions are substantiation-driven: the manual puts the burden of proof on the taxpayer, so the records discipline matters.
Common Questions
Is your Colorado assessment defensible?
Send me the notice of value and I'll review it against your district's mill levy and the market evidence at no cost, and tell you in writing whether an appeal makes sense, including when it doesn't. Every case argued by me, contingency only, priced per property.
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