New Castle County, DE property tax deadlines
2 coming property tax dates for New Castle County, Delaware. Each one links to its official source and shows the day LevyDay last checked it.
| Next dates | Bills due | Last day without penalty | Appeal by | Exemption filing |
|---|---|---|---|---|
| New Castle | Dec 31, 2026legis.delaware.govOct 21 | Not on file | Mar 14, 2027 Sundelcode.delaware.govOct 21 | Not on file |
Deadlines in date order
| Date and source | Deadline |
|---|---|
| March 14 every yeardelcode.delaware.govOct 21 | Appeal deadline Appeal your assessment to the Board of Assessment Review File a written appeal on the board's form before March 15. |
| December 31, 2026 2026 onlylegis.delaware.govOct 21 | Bills due 2026 county and school tax bill due A 2026 state law moved this year's deadline from September 30 to December 31. Penalties don't start until January 1, 2027. |
Appealing your assessed value
Appeal by Mar 14, 2027 in 142 daysdelcode.delaware.govOct 21
If you think the county valued your home too high, you can appeal. Filing with the county is free and you can do it yourself.
Get help filing an appeal
After you send your details, we look for an independent appeal firm or attorney to take your case. We'll be in touch once one has agreed. Firms usually charge a share of what you save, and the one that takes it may pay LevyDay a referral fee.
LevyDay doesn't file appeals or give legal or tax advice. We only pass your details on. The independent firm or attorney that takes your case does the work and sets its own fee.
Get help filing an appealIf you pay late
- Late payment penalty: Late tax gets a 6% penalty, then 1% of the unpaid balance on the first of every month until you pay. delcode.delaware.govOct 21
Official offices
Places in New Castle County
Among them: Arden, Ardencroft, Ardentown, Bear, Bellefonte, Brookside, Claymont, Clayton, Delaware City, Edgemoor, Elsmere, Glasgow, Greenville, Hockessin, Middletown, Newark, New Castle, Newport, North Star, Odessa, Pike Creek, Pike Creek Valley, Port Penn, St. Georges, and 4 more. Every place in the county gets the dates above.