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Updated 2025 Tax Year

New Castle County
Property Tax Guide

Everything you need to know about property taxes in New Castle County, DE. Rates, due dates, exemptions, and how it affects your monthly payment.

7 Official Sources
8 min read
Quick Facts
Tax Rate
$0.1575 per $100 assessed value (base county rate), varies by municipality and school district
Exemptions
4+ Available
Section 1

How Property Tax Works

New Castle County operates Delaware's largest property tax system, serving over 180,000 property owners across unincorporated areas and multiple municipalities. Property taxes are the primary funding source for county services including schools, public safety, parks, and infrastructure maintenance. The county uses a market value assessment system where properties are periodically reassessed to reflect current market conditions.

Property tax rates in New Castle County vary significantly by location due to multiple taxing districts and municipal boundaries. The base county rate for unincorporated areas is $0.1575 per $100 of assessed value for FY 2025-2026, while incorporated areas like Arden ($0.1433) and Ardencroft ($0.1448) have different rates. School district taxes, municipal taxes, and special assessments can substantially increase the total effective rate. Property owners typically pay between 0.5% to 1.2% of their home's assessed value annually, depending on their specific location and applicable district taxes.

Section 2

What Makes Up Your Tax Bill

ComponentRate (per $100)Description
Base County Tax (Unincorporated)$0.1575Core county services, parks, public safety
Arden Municipality$0.1433Municipal services for Arden residents
Ardencroft Municipality$0.1448Municipal services for Ardencroft residents
School District TaxVariesLocal school funding (rates vary by district)
Special AssessmentsVariesFire districts, sewer, water districts
Municipal Property Tax$0.04310City of New Castle (where applicable)

Rates shown are for levy year 2025-2026 and subject to annual budget adoption. Total effective rates range from approximately $0.50 to $1.20 per $100 of assessed value depending on location and applicable special districts. Property owners should verify their specific tax districts through the county's ParcelView system.

Section 3

When Are Property Taxes Due?

For the 2025/2026 tax year in New Castle County, property taxes are due in two installments:

Pro tip: If you pay through mortgage escrow, your lender splits these payments across your monthly mortgage. If you pay directly, set calendar reminders to avoid late penalties.
Section 4

Supplemental Tax Bills

Supplemental taxes are additional property tax bills issued when assessable changes occur to a property during the tax year. Common triggers include new construction completion, property improvements exceeding $1,000, ownership transfers that remove existing exemptions, or subdivision of parcels. These taxes are calculated on a pro-rated basis from the date the change becomes effective through the end of the current fiscal year.

For example, if a homeowner completes a $50,000 addition on January 1st that increases their assessed value, they would receive a supplemental tax bill covering the additional tax liability for the remaining months of the fiscal year. The calculation takes the increased assessed value, applies the applicable tax rate, and pro-rates it based on the effective date. New Castle County has implemented Ordinance 25-099, which provides penalty abatement options for eligible residential taxpayers facing increased tax liability following county-wide reassessments, including installment payment plans.

Example Calculation

Example 1: $300,000 Home (Unincorporated Area)

  • Market Value: $300,000
  • Assessed Value: $300,000
  • Senior Property Tax Credit Applied: -$500 (if eligible, requires application)
  • Net Taxable Value: $300,000
  • Combined Tax Rate: $0.65 per $100 (county + school district)
  • Annual Tax: $1,950
  • Monthly Escrow: $163

Example 2: $600,000 Home (City of New Castle)

  • Market Value: $600,000
  • Assessed Value: $600,000
  • Homestead Assessment Credit: Limits annual assessment increase to 10% (requires application)
  • Net Taxable Value: $600,000
  • Combined Tax Rate: $0.85 per $100 (county + municipal + school)
  • Annual Tax: $5,100
  • Monthly Escrow: $425

Example 3: $1,000,000 Home (Arden)

  • Market Value: $1,000,000
  • Assessed Value: $1,000,000
  • No credits applied
  • Net Taxable Value: $1,000,000
  • Combined Tax Rate: $0.75 per $100 (Arden rate + school district)
  • Annual Tax: $7,500
  • Monthly Escrow: $625

Note: All tax credits require separate applications and have specific eligibility requirements. Rates vary by exact location and applicable taxing districts.

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Section 5

Escrow & Property Taxes

Most mortgage lenders in New Castle County require property tax escrow accounts to ensure timely tax payments. Lenders collect monthly escrow payments equal to approximately 1/12th of your annual property tax bill, plus a small cushion for rate increases. The county's fiscal year runs from July 1 to June 30, with tax bills typically mailed in July and due dates varying by payment plan selected.

Property owners can verify their escrow payments by accessing their tax information through the county's online portal at https://www.nccde.org/186/Receiver-of-Taxes. The Receiver of Taxes office processes payments from both individual property owners and mortgage servicers. When your assessment changes due to reassessment or improvements, notify your lender immediately so they can adjust your escrow payments accordingly. Escrow shortages may occur when tax increases exceed the lender's projections, requiring catch-up payments or increased monthly collections.

How HonestCasa Helps
  • Understand whether your escrow is set correctly
  • See how rising taxes will change your monthly payment
  • Plan ahead instead of being surprised by "shortage" letters
Section 6

Frequently Asked Questions

Q: When are property taxes due in New Castle County? A: Tax bills for FY 2025-2026 are typically mailed in July 2025. Due dates vary based on payment method - annual payments are usually due by September 30th, while quarterly and monthly payment plans have different schedules. Check your specific bill or visit the Receiver of Taxes website for exact dates.

Q: What tax credits are available and do they require applications? A: New Castle County offers several tax credits including Senior Property Tax Credit, Disabled Veterans Credit, and Agricultural Assessment Credit. ALL credits require separate applications and annual renewals - they are NOT automatically applied. Contact the Assessment Office at https://www.nccde.org/174/Assessment for applications and eligibility requirements.

Q: How does the Homestead Assessment Credit work? A: The Homestead Credit limits annual assessment increases to 10% for owner-occupied properties, helping provide tax stability. This credit does NOT reduce your property's market value - it caps how much your taxable assessment can increase each year. You must apply for this credit; it is not automatic.

Q: How often are properties reassessed? A: New Castle County conducts periodic county-wide reassessments to ensure properties reflect current market values. Individual properties may also be reassessed when improvements are made. Assessment notices are mailed to property owners with appeal procedures and deadlines clearly outlined.

Q: What are the penalties for late payment? A: Late payments incur penalties and interest charges. However, Ordinance 25-099 provides penalty abatement opportunities for eligible residential taxpayers affected by reassessment-related tax increases. Payment plan options may be available to qualified property owners.

Q: Can I pay my taxes online? A: Yes, New Castle County offers online payment options through their official portal. You can also set up payment plans and view your tax history. Visit https://www.nccde.org/186/Receiver-of-Taxes for secure online payment options.

Q: Why do tax rates vary within the county? A: Tax rates vary based on your property's location within different taxing districts including municipalities (Arden, Ardencroft, etc.), school districts, fire districts, and special assessment areas. Use the county's ParcelView system to identify all districts that apply to your property.

Q: How do I appeal my property assessment? A: Assessment appeals must be filed within specific timeframes after receiving your assessment notice. The Assessment Office provides detailed appeal procedures and forms. Contact https://www.nccde.org/174/Assessment for current appeal deadlines and requirements for your assessment year.

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