Assessment Ratio
100% (but outdated base years)
Appeal Deadline
Varies by county (2026)
Official Form
Board of Assessment Review form
Risk of Increase
No
How Assessment Works in Delaware
Delaware nominally assesses at 100% of fair market value, but most counties use outdated base years (some decades old), meaning assessed values are far below current market value. The effective ratio depends on when your county last reassessed.
How to File in Delaware
File an appeal with your county Board of Assessment Review. Deadlines and procedures vary by county. Contact your county assessment office for details.
Step-by-Step
Delaware Appeal Process
Review your property assessment on the county's records.
Contact the county assessment office to discuss your assessment informally.
File a written appeal with the Board of Assessment Review by the county deadline.
Attend the hearing and present comparable sales evidence adjusted for the base year.
If denied, appeal to the Superior Court.
FAQ
Delaware Property Tax Appeal Questions
Why are Delaware assessed values so low?
Most Delaware counties haven't reassessed properties in decades. The assessed values reflect market conditions from the base year, not current values. This means your assessed value may be a fraction of your home's current market value.
Can my Delaware assessment increase on appeal?
No. Delaware generally does not increase assessments during the appeal process. Your assessment can stay the same or be reduced.
How do I compare my assessment to neighbors in Delaware?
Because of outdated base years, you should compare your assessment ratio (assessed value divided by market value) to similar properties in your area, rather than comparing raw assessed values.
What is the effective property tax rate in Delaware?
Delaware property tax rates vary by county, municipality, and school district, but the effective rate (annual tax paid divided by market value) typically ranges from about 0.5% to 2.5%. Because Delaware assesses property at 100% (but outdated base years) of market value, your actual tax bill depends on both the assessed value and the local millage or mill levy applied on top of it. If your assessed value is higher than comparable sales support, filing a appeal is one of the only ways to reduce your effective rate without waiting for a reassessment.
How long does a property tax appeal take in Delaware?
Most Delaware appeals take between 6 weeks and 6 months from filing to final decision. After you file Board of Assessment Review form, the assessor or review board schedules a hearing — typically within 30 to 90 days — and issues a written decision shortly after. Cases that settle informally resolve faster, while cases that advance to a formal hearing or court appeal can take several additional months. ProtestMax prepares your full evidence packet in minutes so you can file immediately and start the clock.
Can I appeal my property taxes every year in Delaware?
Yes. In Delaware, homeowners generally have the right to appeal their property tax assessment every year, as long as you file by the Varies by county (2026) deadline. Even if you won a reduction last year, your assessor can revalue your property the following year, and you retain the right to challenge the new value. Annual appeals are especially important during years when market values are flat or falling but assessments keep rising.
What evidence is most persuasive in Delaware hearings?
The strongest evidence in a Delaware appeal hearing is recent comparable sales — homes similar to yours in size, age, condition, and location that sold for less than your assessed value within the last 6 to 12 months. Equity comparisons (similar homes assessed for less than yours) are also highly persuasive. Photos of deferred maintenance, structural issues, or negative location factors (busy roads, flood zones, power lines) strengthen your case further. ProtestMax assembles all of this evidence into a hearing-ready packet tailored to Delaware's rules.