Property Assessment Appeals in New Castle County, Delaware
New Castle County's Office of Finance Assessment Division maintains the annual property assessment, and the Board of Assessment Review hears administrative appeals alleging an improper assessment. The 2026 annual legal notice set March 14 as the filing deadline for the July 2026 through June 2027 roll. Supplemental or later assessment notices may use a different period. The FairPath owner-guided evidence packet remains available year-round for every New Castle County property. It can organize the notice, parcel record, homeowner-reviewed corrections, comparable sales, property-condition material, the county form, and official source links. FairPath does not decide which deadline applies, file the appeal, choose the owner's asserted fair market value, communicate with the Assessment Division or Board, appear at a hearing, or represent the owner.
Assessment context: New Castle County states that property on the current annual roll is assessed at fair market value as of July 1, 2024, the county's most recent reassessment base date. The official Parcel Search exposes parcel identity, owner and tax information, sales history, assessment data, and property characteristics. Review the selected parcel and tax year against the assessment notice before using any comparison. A current tax bill combines the assessment with county, school, and other tax rates and is not itself evidence that the fair-market-value assessment is wrong. Separate public county facts, homeowner corrections, later physical changes, comparable-sale information, and any appraisal or contractor material. If the dispute concerns classification, exemption, supplemental construction, or a municipal charge rather than annual fair market value, label that issue and verify the correct path.
Filing process: Begin with the current county legal notice, Parcel Search record, Board of Assessment Review page, residential form, formal appeal guide, and rules of procedure. The 2026 guide requires the parcel number and the value the owner believes represented fair market value as of July 1, 2024. It describes competent evidence of substantial overvaluation and identifies comparable sales, cost, or income approaches, with residential owners commonly using comparable sales. Follow the current form for signatures, copies, supporting material, delivery, and receipt deadline; the county's 2025 reassessment FAQ and the later 2026 annual notice are different records and should not be merged. Preserve the completed form, evidence index, delivery proof, hearing notice, Board decision, and any separate Superior Court record for homeowner review.
Evidence to review: Tie each exhibit to the July 1, 2024 fair-market-value base date identified by New Castle County and to the actual assessment issue. Use Parcel Search to verify the parcel number, land and improvement values, sale history, building characteristics, use, and other recorded facts. For comparable evidence, record county parcels with address, sale date and price, size, age, use, construction, condition, location, and material differences; use sales from the period identified by the current county guide when that guide applies. Add dated photographs, inspections, surveys, permits, contractor scopes, or owner records when they document a characteristic the county record may not reflect. An estimate or repair cost should be labeled as owner-provided support, not as an independently verified reduction. The homeowner reviews and approves every correction and factual assertion before it enters the packet.
Current deadline guidance: 2026 annual assessment appeal deadline was March 14. New Castle County's legal notice for the July 1, 2026 through June 30, 2027 annual assessment states that a written appeal had to be filed with the Board of Assessment Review no later than March 14, 2026. Delaware law describes the annual written-notice requirement before March 15, while a supplemental assessment can follow a different notice-relative period. The current assessment type, notice, county form, and live Board instructions must therefore be checked together.
The 2026 annual roll uses a July 1, 2024 fair-market-value reassessment base date.
The county's legal notice set March 14, 2026 for annual appeals on the July 2026 through June 2027 roll.
The Board's 2026 guide requests competent evidence and an owner's asserted fair market value as of the base date.
Annual, supplemental, classification, exemption, and municipal issues can follow different records or procedures.
Official filing authority: New Castle County Office of Finance, Assessment Division and Board of Assessment Review. https://www.newcastlede.gov/390/Board-of-Assessment-Review
Source: New Castle County Office of Finance, 2026-2027 Annual Assessment Legal Notice, https://www.newcastlede.gov/DocumentCenter/View/26129/Legal-Notice. Reviewed 2026-08-06.
Source: New Castle County, Board of Assessment Review, https://www.newcastlede.gov/390/Board-of-Assessment-Review. Reviewed 2026-08-06.
Source: New Castle County, 2026 Formal Property Assessment Appeal Guide, https://www.newcastlede.gov/DocumentCenter/View/62987/NCC---Guide-to-Property-Assessment-Appeals. Reviewed 2026-08-06.
Source: New Castle County, Assessment Division and Parcel Search, https://www.newcastlede.gov/181/Assessment. Reviewed 2026-08-06.
Source: Delaware General Assembly, Delaware Code Title 9 Chapter 83, https://delcode.delaware.gov/title9/c083/sc01/. Reviewed 2026-08-06.
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