Every fact on this site is dated, sourced, and honestly labelled
Property tax rules change every legislative session — and a missed deadline usually can't be fixed until next year. Most property tax websites say "updated 2026" at the page level and leave you guessing about each fact. We publish a per-state confirmation status instead: which deadlines we have actually read off the official source, when, and which ones we haven't. A deadline we have not confirmed is labelled as unconfirmed on the state page itself, rather than being dressed up in the same badge as one we checked this morning.
How verification works
Every state's appeal deadline and assessment ratio lives in a single source-of-truth file with a verification month and official source URL. State guides, the tax calendar, and the tax-code reference all derive from it — a fact is corrected once and every page reflects it.
An automated check runs in the build pipeline and fails the deploy if any page's stated deadline or tax rate diverges from the canonical facts file. Worth being precise about what that buys you: it proves our pages agree with each other, not that what they agree on is correct. Consistency is not accuracy — the confirmation status in the table below is what speaks to accuracy.
Every night an automated scan sweeps county records for broken official links, missing assessor contacts, and data gaps, and files proposals for human review. Nothing is silently auto-published — but nothing silently rots, either.
Each data domain has a review cadence (annual for statutory facts, matched to source-release cycles for Census and rate data). The current status of every domain is shown below — including when a review is coming due.
Live review status by data domain
Per-state verification table
Appeal deadline on record, when it was verified, and the official source.
| State | Appeal deadline (standing rule) | Confirmed | Source |
|---|---|---|---|
| Alabama | 30 days from the written notice of valuation (County Board of Equalization) | August 2026 | Official |
| Alaska | 30 days from the date your assessment notice was MAILED — appeal to the assessor | August 2026 | Official |
| Arizona | 60 days after the notice of value to the assessor — filed in the VALUATION year, one year ahead of the tax year | August 2026 | Official |
| Arkansas | Third Monday in August — August 17, 2026 to apply to the County Board of Equalization | August 2026 | Official |
| California | July 2 – November 30 (most counties); September 15 in 11 counties (Alameda, Alpine, Inyo, Kings, Mono, Placer, San Francisco, San Luis Obispo, Santa Clara, Sierra, Ventura) | August 2026 | Official |
| Colorado | June 8 for the 2026 protest season (real property protest to the assessor); June 1 from 2027 onward | August 2026 | Official |
| Connecticut | February 20 — or March 20 in any town whose assessor took a grand-list extension (Board of Assessment Appeals) | August 2026 | State statute |
| Delaware | Set per county — New Castle: March 14; Kent: last working day in January (Jan 30, 2026, 5pm, no postmark); Sussex: March 15 | August 2026 | State statute |
| District of Columbia | April 1 — first-level petition to the Office of Tax and Revenue (NOT directly to RPTAC) | August 2026 | State statute |
| Florida | 25 days from TRIM notice (typically mid-September) | August 2026 | Official |
| Georgia | 45 days from assessment notice | August 2026 | State statute |
| Hawaii | Varies by county — Honolulu: January 15; Maui & Hawaii County: April 9; Kauai: December 1–31 of the PRECEDING year | August 2026 | Official |
| Idaho | 4th Monday in June — Monday June 22, 2026, by close of county business hours | August 2026 | Official |
| Illinois | 30 days from PUBLICATION of the assessment list outside Cook County; per-township dates in Cook | August 2026 | Official |
| Indiana | June 15 — of the assessment year if Form 11 was mailed before May 1, otherwise of the year taxes are payable | August 2026 | State statute |
| Iowa | April 2 – April 30, 2026 (Board of Review) — you cannot file before April 2 | August 2026 | Official |
| Kansas | 30 days from the mailing of your notice (equalization appeal), OR pay under protest — Dec 20, 2026 for the second route | August 2026 | Official |
| Kentucky | One workday AFTER the open inspection period closes — May 19, 2026 on the standard calendar (PVA conference required first) | August 2026 | Official |
| Louisiana | During the 15-day open-rolls window (between Aug 15 and Sep 15) — complaint to the parish Board of Review at least 7 days before its hearing; Orleans: within 3 business days of the last exposure date | August 2026 | State statute |
| Maine | 185 days from commitment for the assessor abatement; then 60 days from denial to the Board of Assessment Review | August 2026 | State statute |
| Maryland | 45 days from your notice; 60 days for new owners; or a Petition for Review by January 1 in an off-cycle year | August 2026 | Official |
| Massachusetts | Due date of the first installment of your ACTUAL tax bill — February 1 only in quarterly-billing municipalities | August 2026 | Official |
| Michigan | March Board of Review (required first step for residential); Michigan Tax Tribunal by July 31 (residential) / June 1, 2026 (commercial-industrial) | August 2026 | Official |
| Minnesota | Local Board of Appeal and Equalization (April 1 – May 31) first; Tax Court petition by April 30 | August 2026 | Official |
| Mississippi | First Monday in August — August 3, 2026 (objection at the County Board of Supervisors' August meeting) | August 2026 | Official |
| Missouri | Second Monday in July — July 13, 2026 (County Board of Equalization) | August 2026 | State statute |
| Montana | 30 days from the date on your notice; in an intervening year with no new notice the deadline is June 1 | August 2026 | Official |
| Nebraska | June 1 – June 30, 2026 — filed with the county CLERK on Form 422 | August 2026 | Official |
| Nevada | January 15 for the FOLLOWING fiscal year — Thursday January 15, 2026 (no rollover in 2026) | August 2026 | Official |
| New Hampshire | March 1 following the FINAL tax bill (abatement to the municipality); BTLA or Superior Court — not both — by September 1 | August 2026 | Official |
| New Jersey | April 1 (County Board of Taxation); May 1 after a revaluation or reassessment; January 15 in Burlington, Gloucester and Monmouth | August 2026 | Official |
| New Mexico | The later of April 1 or 30 days after the Notice of Value was mailed — petition filed with the county ASSESSOR | August 2026 | Official |
| New York | Grievance Day (4th Tuesday in May for most municipalities); New York City is excluded — March 1 / March 15 | August 2026 | Official |
| North Carolina | Before the County Board of Equalization and Review adjourns — a county-specific date, not a 30-day clock | August 2026 | State statute |
| North Dakota | Local board in April (cities: first 15 days), then county board June 1–10, 2026 — there is no 30-day-from-notice rule | August 2026 | State statute |
| Ohio | March 31 (County Board of Revision) | August 2026 | Official |
| Oklahoma | 30 days from notice to the county ASSESSOR (Form 974), then 15 days from that decision to the County Board of Equalization (Form 976) | August 2026 | State statute |
| Oregon | December 31 (petition the county Property Value Appeals Board) | August 2026 | Official |
| Pennsylvania | September 1 (County Board of Assessment Appeals); a county may set an earlier date, but no earlier than August 1 | August 2026 | Official |
| Rhode Island | On or before November 15 — and not less than 90 days after the first tax payment is due (RIGL 44-5-26) | August 2026 | State statute |
| South Carolina | 90 days from the date the assessor mailed your notice — and in a NO-NOTICE year you may appeal in writing at any time | August 2026 | Official |
| South Dakota | March 12, 2026 — written appeal to the LOCAL board of equalization (postmark counts) | August 2026 | Official |
| Tennessee | County board convenes June 1 and sets its own filing deadline — confirm with your assessor (Shelby convenes May 1) | August 2026 | State statute |
| Texas | May 15 (or 30 days after notice, whichever is later) | August 2026 | Official |
| Utah | The LATER of September 15 or 45 days from your valuation notice (County Board of Equalization) | August 2026 | Official |
| Vermont | 14 days from the grievance result to the Board of Civil Authority; then 30 days from the BCA decision to the State Appraiser | August 2026 | State statute |
| Virginia | Set by your locality for the Board of Equalization — there is no statewide BOE deadline; circuit court is the later of 3 years from the last day of the tax year or 1 year from the assessment | August 2026 | State statute |
| Washington | July 1, or 30 days after the notice of value was mailed — whichever is later (County Board of Equalization) | August 2026 | Official |
| West Virginia | February 20, 2026 — written protest; hard outer deadline March 31, 2026 to the Office of Tax Appeals | August 2026 | Official |
| Wisconsin | Notice of intent at least 48 hours before the Board of Review's first meeting, plus Form PA-115A within its first two hours | August 2026 | Official |
| Wyoming | Within 30 days of the assessment schedule date or postmark — filed with the county ASSESSOR, not the board | August 2026 | Official |
"Confirmed" means a person read that deadline off a primary source — the state's own revenue department publication, the statute text, or the county authority that sets the date — in the month shown. "Not confirmed" means the entry has been reviewed and is sourced as best we can, but nobody has checked it against the official source. Treat those as a starting point for your own call to the county, not as an answer.
We split these apart in August 2026 after auditing all 51 deadlines. Sixteen were wrong and fourteen materially incomplete — several in ways that forfeit an appeal rather than merely filing it late. Every one of them had been carrying the same confident "verified" badge as the deadlines we had actually checked. A single site-wide stamp applied to unequal data is worse than no stamp at all, so we stopped using one.
Counties can change dates mid-year, and many deadlines vary by county or by when your notice was mailed — so every deadline we publish also says how it varies, and we always tell you to confirm with your county before filing. Where we don't have sourced data (for example, county win-rate analytics in most states), we show "N/A" rather than an estimate dressed up as a fact.