Enterprise
Individual & Small Business
| Payment | Delaware due date |
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| 1 | |
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Federal 2026 estimated tax due dates, for comparison: April 15, 2026, June 15, 2026, September 15, 2026, January 15, 2027.
Who must pay Delaware estimated tax?
Every resident and non-resident individual shall make a declaration of estimated tax for the taxable year if the tax due in excess of withholding can reasonably be expected to exceed $800.00.
How do you avoid a Delaware underpayment penalty?
1 1/2% per month penalty on underpaid installments does not apply if each installment is timely and is at least 90% (66 2/3% farmers/fishermen) of the current-year tax, or 100% of the tax shown on the prior year's return (110% if prior-year federal AGI exceeded $150,000; $75,000 MFS). Not required if there was no tax liability in the prior year.
Are there local estimated payments?
City of Wilmington earned income / net profits tax is administered by the City of Wilmington, not the Delaware Division of Revenue, and is not paid with state estimated tax.
How much should you pay?
Start with your federal estimate: the free Quarterly Estimated Tax Calculator works out your 2026 federal payments and safe harbor. Delaware figures its own tax, so the state amount is separate.