Rate Breakdown

Property taxes in New Castle County are calculated by multiplying the assessed value (minus exemptions) by the total local millage rate.

How Property Tax Works in New Castle County

In New Castle County, property tax is calculated by multiplying the assessed value of a parcel by the applicable millage rates. The County Assessor’s Office conducts the assessment each year, typically on a roll‑date of January 1. The assessed value is meant to represent the market value of the property as of that date, adjusted for any improvements, depreciation, or changes in use. Once the value is determined, the tax bill is generated by applying several components:

• County millage rate – set annually by the New Castle County Council to fund services such as schools, roads, and public safety.
• Municipal millage rate – levied by the city or town in which the property resides (e.g., Wilmington, Newark).
• Special district rates – may include fire districts, library districts, or other local entities.

Each “mill” equals one‑tenth of one percent, or $1 of tax for every $1,000 of assessed value. For example, a combined millage of 12.50 mills on a home assessed at $200,000 generates a tax liability of $2,500 for the fiscal year.

Available Exemptions

Delaware offers several exemptions that can reduce the taxable portion of a property’s assessed value. Eligibility criteria vary, but the most common exemptions include:

• Homestead exemption – provides a $25,000 reduction for primary residences. The homeowner must occupy the property as the principal dwelling.
• Senior citizen exemption – residents age 65 or older may receive an additional $15,000 exemption if their household income falls below the state‑set threshold.
• Disability exemption – a $15,000 reduction for qualified individuals with a permanent physical or mental disability, as documented by a medical professional.
• Veteran exemption – active‑duty or honorably discharged veterans (and surviving spouses) may qualify for a $15,000 exemption, with an extra $10,000 if the veteran was disabled in service.

All exemptions are applied before the millage rates are calculated, effectively lowering the taxable base. Applications are submitted to the New Castle County Assessor’s Office and must be renewed annually.

Payment Schedule & Deadlines

New Castle County follows a two‑installment schedule for property taxes:

• First installment – due on July 1. Paying by this date secures a 5 % discount on the total amount owed.
• Second installment – due on December 31. No discount is available, but interest does not accrue if paid by this deadline.

Taxpayers may also opt for a quarterly automatic debit plan, which spreads the liability over four payments (January 1, April 1, July 1, and October 1). Late payments after December 31 incur a 2 % penalty plus interest calculated at the state’s statutory rate. Persistent delinquency can result in a tax lien, eventual foreclosure, and loss of the property.

Appealing Your Assessment

If you believe your property has been assessed incorrectly, you have the right to file an appeal with the New Castle County Board of Assessment Appeals (BAA). Follow these steps:

• File a Notice of Appeal – submit the form within 30 days of receiving your assessment notice.
• Gather supporting evidence – include recent comparable sales, an independent appraisal, or documentation of property damage.
• Attend the hearing – the BAA will schedule a public hearing where you can present your case.
• Receive the decision – the Board issues a written determination, typically within 60 days of the hearing.

If the BAA’s decision is unfavorable, you may further appeal to the Delaware Superior Court. Throughout the process, maintain clear records and adhere to all filing deadlines to protect your rights.