CO · 2026 appeal calendar

Colorado Property Tax Appeal Deadlines 2026.

Colorado property tax appeal deadlines and filing windows for commercial real estate. Verify with your local assessor or appeal board for the specific jurisdiction before filing.

Updated May 2026

Verify before filing. Statutory deadlines change, and many counties operate on their own schedule inside the state framework. Always confirm the current year's window with the assessor or appeal board for the specific jurisdiction before relying on a date.

2026 appeal calendar

Colorado deadlines at a glance.

State-level deadlines plus major sub-jurisdictions where the schedule diverges from the state default. Where a column says "Varies," confirm the date with the local assessor.

Month Type Event Date Details
April BPP
Filing Deadline
15-Apr
May RP
Value Notices Issued
1-May
May BPP
Value Notices Issued
May-Jun
June RP
Appeal Deadline
1-Jun
June BPP
Appeal Deadline
30-Jun
December Both
Abatement Deadline
31-Dec Abatement petitions may be filed within two years of the date the taxes were due, provided that: the property valuation has not been previously protested, and the person or entity filing for abatement was the owner of record for the year(s) being abated.

RP = Real Property · BPP = Business Personal Property · Both = Applies to both

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