Wilmington, Delaware: Inside or Outside the City Line?

Part of our Delaware Retirement and Second Home Guides

By Christine Davis, REALTOR, Active Adults Realty, Lewes. Recorded October 14, 2026. Figures checked October 19, 2026.

Prefer to read? The full guide is written out below.

Please read first: Active Adults Realty is not a tax advisor, an accounting firm or a taxing authority. This page is general information, not legal, tax or financial advice. Rates are set by the City of Wilmington, New Castle County, your school district and your water provider, and they change. Check anything you plan to rely on with your own advisor and the taxing authority.

Is a Wilmington address inside the city?

Not always. Two houses can both have a Wilmington mailing address, and only one of them is actually in the City of Wilmington. The city line, not the mailing address, decides which bills arrive.

Does the City of Wilmington tax your income?

Yes, inside the city. The City of Wilmington wage tax is 1.25 percent of gross wages, and it applies to employees who live in the city or work in the city. If you or a spouse still work, where the work happens matters as well as where you live. Pension, Social Security and IRA questions go to your own tax person.

What is on the property tax bill inside the city?

Inside the city line you pay a City of Wilmington property tax on top of the county and school taxes. The city's fiscal year 2027 budget, effective July 1, 2026, made no increase to the city property tax rate.

Outside the city, in unincorporated New Castle County, there is no city bill. The county raised its property tax rate 17.2 percent for fiscal year 2027. The county puts that at about $102 a year, or about $8.50 a month, for the median homeowner on a $378,000 property.

Who sends the water and sewer bill?

Inside the city, the City of Wilmington runs water and sewer. Its fiscal year 2027 budget limited water and sewer increases to 7 percent. Outside the city, New Castle County raised its sewer consumption rate 5 percent for fiscal year 2027, and water may come from a private water company or a well. Some homes are on septic.

How do you know which side of the line a house is on?

• The tax bills: a city bill is there or it is not.
• The New Castle County parcel record for the address.
• The City of Wilmington wage tax address guide.
• Who provides the water.

If they do not agree, sort it out before you sign.

What should you ask for before you buy?

The last full year of every tax bill, city, county and school, and a recent water and sewer bill with how often it comes. Neither side of the line is simply cheaper. Put the real bills side by side, and do not rely on a listing sheet for the tax figure.

Want us to check a street?

Send us the street and we will tell you which side of the city line it sits on and help you pull the real bills before you make an offer. If you own in or around Wilmington and are thinking about selling, we will tell you what a buyer is going to ask for and what to have ready. It costs you nothing.

Active Adults Realty
1504 Savannah Road, Lewes, DE 19958
302-549-5164
Office: 302-424-1890
Contact us

Sources: City of Wilmington Wage Tax Information, New Castle County document center (wage tax 1.25 percent of gross wages for employees who live or work in the city). City of Wilmington, "Mayor Carney Signs FY '27 Budget," and Delaware Public Media, May 30, 2026 (no city property tax rate increase; water and sewer increases limited to 7 percent; effective July 1, 2026). New Castle County news release, May 26, 2026 (17.2 percent property tax rate increase for unincorporated New Castle County, about $102 a year on the $378,000 median property; sewer consumption rate up 5 percent). Figures checked October 19, 2026.