When Are Maryland Taxes Due for Individuals and Businesses?

Maryland’s income tax returns for individuals and most businesses are due April 15, the same day as the federal deadline. That one date covers resident and nonresident income tax, corporate income tax, pass-through entity returns, and the annual report filed with the State Department of Assessments and Taxation. Everything else — estimated payments, employer withholding, sales tax, property tax, and estate tax — runs on its own schedule. If you’re asking when Maryland taxes are due, the honest answer is that it depends on which tax, and missing any of the dates below starts the penalty and interest clock.

Individual Income Tax

Maryland residents file Form 502 and nonresidents file Form 505 by April 15 of the year after the tax year. For 2025 returns, the deadline is April 15, 2026. If April 15 falls on a weekend or federal holiday, filing moves to the next business day.1Comptroller of Maryland. Resident Income Tax Booklet

Maryland layers a local income tax on top of the state tax, and both go on the same return. Every county and Baltimore City sets its own rate. Starting with tax year 2026, the maximum rate counties can impose rises to 3.30%, and several counties have already adopted higher rates.2Comptroller of Maryland. Tax Alert – Changes to Standard and Itemized Deductions and to State and Local Income Tax Rates There’s no separate local return, but the combined rate affects whether withholding alone will cover your bill.

Quarterly Estimated Payments

If you expect to owe Maryland tax that isn’t covered by withholding, you generally have to pay in quarterly. The schedule matches the IRS. For tax year 2026 the dates are:

  • First quarter: April 15, 2026
  • Second quarter: June 15, 2026
  • Third quarter: September 15, 2026
  • Fourth quarter: January 15, 2027

Paying less than 90% of your current-year tax or less than 110% of last year’s tax between withholding and estimates triggers an underpayment penalty.3Comptroller of Maryland. Form 502UP – Underpayment of Estimated Income Tax by Individuals Nonresidents with Maryland-source income follow the same quarterly schedule.

Business Income Tax

C corporations file Form 500 by the 15th day of the fourth month after their tax year closes. For calendar-year filers that’s April 15.4Library of Maryland Regulations. COMAR 03.04.03.04 – Filing of Returns Partnerships, S corporations, LLCs taxed as partnerships, and business trusts file Form 510 on the same timetable.5Maryland Comptroller of the Treasury. 2024 Form 510 – Pass-Through Entity Income Tax Return Instructions Pass-through entities use the 510 both to report flow-through income and to remit taxes withheld on behalf of nonresident owners.

Maryland does not grant extra time to pay business tax, only extra time to file. The balance due is still expected on the original deadline.

Employer Withholding

If you withhold Maryland income tax from employee wages, you remit it using Form MW506 on a schedule the Comptroller assigns you. The five categories work like this:6Comptroller of Maryland. 2025 Maryland Employer Withholding Guide

  • Accelerated filers (those who withheld $15,000 or more in the prior year) must remit within three business days of any payroll that pushes accumulated withholding to $700 or more.
  • Monthly filers (more than $700 withheld in any quarter) remit by the 15th of the following month.
  • Quarterly filers (less than $700 per quarter) remit by April 15, July 15, October 15, and January 15.
  • Annual filers (less than $250 per year) remit by January 15 of the following year.
  • Seasonal filers remit only during their active months after approval.

Every employer also files Form MW508, the annual reconciliation, by January 31 following the tax year.6Comptroller of Maryland. 2025 Maryland Employer Withholding Guide

SDAT Annual Report and Business Personal Property Return

This one trips up new business owners because it isn’t filed with the Comptroller. Every business entity registered in Maryland must file a combined Annual Report and Personal Property Tax Return (Form 1) with the State Department of Assessments and Taxation by April 15.7Maryland Department of Assessments and Taxation. 2026 Form 1 Annual Report and Business Personal Property Return Corporations, LLCs, partnerships, and business trusts all have to file whether or not they own personal property.

Late filing starts at a $30 minimum penalty and can reach $500, with an additional 2% of that initial amount added every 30 days the report stays unfiled.8Maryland Department of Assessments and Taxation. 2025 Business Entity Annual Report Form 1 Instructions An extension is available for the personal property portion through SDAT’s online portal, but the annual report itself is still expected on time.

Sales and Use Tax

Maryland’s 6% sales and use tax is remitted on a monthly, quarterly, semi-annual, or annual schedule depending on your sales volume. Whatever your frequency, the return is due by the 20th day of the month after the reporting period ends.9Comptroller of Maryland. Business Tax Tip 22 – Maryland Sales and Use Tax A monthly filer reporting January sales files by February 20.

Use tax works the same way for consumers who buy taxable goods out of state without paying sales tax. The amount owed is due by the 20th of the month following the quarter in which the purchase was made.

Property Tax

County and municipal governments send property tax bills in July, and the full annual amount is due by September 30. Any balance remaining on October 1 is delinquent and interest starts to accrue.10Anne Arundel County Government. Real Property Tax

Owner-occupied residential and commercial properties can split the bill in two: the first half by September 30 and the second by December 31. A service charge applies to the second installment, so paying the full amount in September avoids that extra cost.

Estate Tax

Maryland imposes an estate tax on estates valued above $5 million. Form MET-1 and any tax owed are due nine months after the date of death.11Comptroller of Maryland. Form MET 1 – Maryland Estate Tax Return The Comptroller can grant up to six months of additional filing time, and an estate with a federal extension automatically gets the matching Maryland extension.12Maryland General Assembly. Maryland Tax-General Code 7-305.1 – Extension of Time for Filing The payment deadline doesn’t move.

Filing Extensions

Extensions buy you more time to file, not more time to pay. That’s the single most important thing to know before you request one.

Individuals get up to six months, which pushes the deadline to October 15. If you expect to owe nothing and already filed a federal extension on Form 4868, Maryland accepts it automatically.13Library of Maryland Regulations. COMAR 03.04.02.14 – Extension of Time to File If you expect to owe, file Form 502E with your estimated payment by April 15. Any unpaid balance after that date accrues interest and may trigger penalties even with a valid extension.1Comptroller of Maryland. Resident Income Tax Booklet

Business extensions depend on entity type:14Comptroller of Maryland. Online Extensions for Maryland Business Income Tax

Businesses that have filed Form 500 or 510 before and expect a zero balance can request their extension online. First-time filers and anyone with a balance due must submit the paper form with payment.16Comptroller of Maryland. Online Extensions for Maryland Business Tax Returns

Penalties and Interest for Late Filing

Maryland runs penalties and interest separately, and they stack. Interest on unpaid tax starts on the original due date, not when you eventually file. The annual interest rate for calendar year 2025 was 11.4825%, and the Comptroller had not yet published the 2026 rate as of this writing.17Comptroller of Maryland. Maryland Tax Alert – Sales and Use Tax Updates 2025-2026

On top of interest, a failure-to-file or failure-to-pay penalty applies. For income taxes the penalty is calculated as a percentage of the unpaid balance and accrues monthly. For the SDAT annual report it starts at $30, climbs toward $500, and adds a 2% surcharge every 30 days. The Comptroller can reduce or waive penalties when you show reasonable cause, but the burden is on you to ask and to document the reason.

The costliest mistake is treating an extension as more time to pay. It isn’t. If you file Form 502E or 500E to buy more time with the paperwork, the tax is still due April 15, and every dollar unpaid after that date collects both penalty and interest at the current rate.