Warren County is one of the smallest counties in Indiana by population — roughly 8,000 residents spread across a predominantly agricultural landscape anchored by Williamsport, the county seat. The 2026 assessment cycle reaches Warren County the same way it reaches Marion County: every parcel re-trended through the DLGF cost-table reset that pushed statewide assessed values up roughly 12% in the 2025 cycle. Form 11 notices typically arrive in mid-May, the spring tax installment is due May 11, 2026, and the Form 130 appeal window runs 45 days from your specific notice date.
This guide breaks down what's distinctive about Warren County's 2026 cycle, why the small-county dynamics matter for the appeal process, and how to file a Form 130 that survives PTABOA review.
What's Driving Warren County AVs in 2026
1. Farmland Productivity Dominates the Tax Base
Warren County's tax base is dominantly agricultural. Farmland AV is set by base rate per acre adjusted by soil productivity factor — and verifying the productivity factor against your USDA NRCS soil maps is the single most recoverable error in farmland assessment. Indiana farmland values for 2026 reflect a mix of softer commodity prices and continued input-cost pressure, but the assessor's base rate moves on its own schedule and lags the market.
2. Williamsport's Residential and Commercial Base
Williamsport carries Warren County's residential and commercial concentration. Median sale prices are modest, which means even small dollar AV changes can read as larger percentages on Form 11. The right reference point isn't the percentage on the notice — it's the comparable sales in your neighborhood code.
3. Small-County Comparable Sales Pools
With a small parcel count and modest annual transaction volume, individual sales carry disproportionate weight in setting the trended AV for surrounding parcels. A handful of above-market sales in 2024–25 can pull up an entire neighborhood-code AV band, while condition-impaired sales pull values down. Assessors weight arms-length, market-rate transactions most heavily.
Warren County's effective property tax rate is approximately 0.86%, below the national median of 1.02%. That doesn't mean a Form 11 increase doesn't matter — the percentage move on your AV is the same regardless of rate. But the absolute dollar impact of a successful appeal is smaller than in higher-rate counties. Factor that into the appeal-effort calculus.
What to Check on Your Warren County Form 11
Use the statewide Form 11 walkthrough for the general process. Three Warren-specific items deserve focused attention.
Property Class Code
Verify:
- Owner-occupied residence is coded 510, not 511 (rental)
- Farm-with-residence parcels split correctly between the home and the tillable acres
- A homestead farmstead retains the homestead deduction if the owner lives on the farm
- Outbuildings used for farm purposes are coded as ag
Farmland Soil Productivity
Pull your USDA Web Soil Survey report (free) and compare the dominant soil types against the productivity factor on your Form 11. Even a 5–10% misapplied productivity factor compounds across hundreds of acres into a substantial AV — and a substantial appeal opportunity.
Land vs Improvement Split
For Williamsport residential parcels, a spike in land value alone — without a corresponding move in improvement value — is an appeal flag. Compare your land AV per square foot against three or four nearby parcels of similar size.
Warren County By the Numbers
| Metric | Warren County |
|---|---|
| County seat | Williamsport |
| Population (approx.) | 8,000 |
| Effective property tax rate | ~0.86% |
| Constitutional caps | 1% / 2% / 3% |
| Spring tax due | May 11, 2026 |
| Fall tax due | November 10, 2026 |
| Form 11 mailing window | Mid-May 2026 |
Filing a Form 130 in Warren County
Where to File
Form 130 is filed with the Warren County Assessor's Office at the courthouse, 125 N. Monroe Street, Suite 3, Williamsport. Filings are time-stamped on receipt. For any submission in the final week of the window, hand-delivery or certified mail with return receipt is the safe choice.
Evidence Strategy in a Small-Population County
Warren's small parcel count creates an evidence challenge for residential appeals — comparable sales pools within a single neighborhood code can be very thin. Three principles:
- Stay within the neighborhood code first — even thin evidence here outweighs broader-radius alternatives
- Exclude non-arms-length transactions (intra-family, foreclosure, distressed) from your comp set
- For unique properties (large-lot rural homesites, historic structures, river-front parcels), an appraisal often outperforms a comp-set argument
For farmland appeals, USDA NRCS soil productivity documentation is the strongest single piece of evidence. The general Indiana property tax appeal guide walks through Form 130 evidence build in detail.
What Happens After Filing
The PTABOA acknowledges the petition and may extend a written settlement offer based on the evidence. Most Warren County appeals settle on written evidence without a formal hearing. PTABOA hearings typically schedule three to nine months after filing. PTABOA decisions can be escalated to the Indiana Board of Tax Review within 30 days of the written determination.
SB 1 and the Spring 2026 Bill
Warren County homestead owners receive the SB 1 supplemental homestead credit on the spring 2026 bill — 10% of net property tax owed, capped at $300 per homestead. The supplemental homestead deduction also steps from 35% to 40%. Williamsport homestead owners with relatively low effective rates will see modest dollar savings but a meaningful percentage benefit.
The SB 1 credit does not apply to farmland or commercial parcels. For farmland operators, the only mechanism to influence the 2027 bill is the Form 130 appeal on the 2026 Form 11.
Why Cyclical Verification Matters in Warren County
Indiana's cyclical reassessment program physically inspects parcels on a four-year rolling cycle. For Warren County's predominantly rural parcels, the cyclical visit is when outbuildings, condition, and physical changes get verified. Three things to confirm:
- Outbuildings demolished since the last cycle are removed from the record
- Pole barns reclassified for non-ag use are coded correctly
- The base farmland soil productivity factor for your tillable acres matches your USDA NRCS soil maps
If a building has been demolished and is still on file, your AV is overstated. The fix is a written notification to the assessor's office with photographic documentation.
Warren County in the Statewide Picture
Warren sits below the statewide median property tax rate on a per-AV basis and is not represented among the most over-assessed counties. Its small population and dominantly agricultural tax base mean the absolute dollar amounts moving in the 2026 cycle are modest at the county level — but the percentage impact on individual parcels is the same as any other Indiana county.
For owners considering whether the appeal effort is worth it, the rule of thumb in Warren County is that every $10,000 of AV reduction on a Williamsport-area homestead translates to roughly $70–$90 of annual tax savings depending on taxing district. A successful appeal pays back across multiple cycles since the new AV becomes the baseline for future trending.
Find Your Warren County Property
- Warren County overview
- Warren residential parcel data
- Warren commercial parcel data
- Warren industrial parcel data
- Warren agricultural parcel data
For a quick read on your AV versus comparable sales or productivity-class farmland comparables, Property Lookup pulls the relevant comp set. For a contingency-based appeal, Tax Appeal Automation builds the Form 130.