Maryland Form 500E is the Application for Extension to File Corporation Income Tax Return. Filing it by your return’s original due date gives your corporation an automatic seven-month extension to file Form 500. The extension covers the filing deadline only. Any tax you owe is still due on the original date, so you need to estimate your liability on the form and pay the balance to avoid interest and penalties.
Who Files Form 500E and When
Any corporation required to file Maryland Form 500 and unable to meet the original deadline should file Form 500E. The return is normally due on the 15th day of the fourth month after the close of the tax year, which is April 15 for calendar-year corporations.1Maryland Comptroller of the Treasury. Business Income Tax Filing Information That covers C-corporations, S-corporations filing at the entity level, and foreign corporations authorized to do business in Maryland.
There is one shortcut. If you already requested a federal extension from the IRS and you owe no additional Maryland tax, you get an automatic six-month state extension without filing anything.2Maryland Comptroller of the Treasury. Tax Guidance – Extensions In that case, skip Form 500E. You still need to file it when you owe a balance, or when your corporation has never previously filed a Maryland Form 500, even if no tax is due.
One reason to file Form 500E even when you already have a federal extension: the state form grants seven months rather than six. That extra month can matter at year-end.
Filling Out the Form
Form 500E is a single page. Enter your corporation’s nine-digit federal Employer Identification Number, the exact legal name registered with the State Department of Assessments and Taxation, the business address, and the tax year ending date. That identifying information is what lets the Comptroller match the extension to the correct filing period.
The heart of the form is a five-line tax payment worksheet:3Comptroller of Maryland. Application for Extension to File Corporation Income Tax Return
- Line 1: estimated total tax liability for the year.
- Line 2: estimated tax payments already made during the year.
- Line 3: tax credits and prior-year overpayments applied to the account.
- Line 4: total of lines 2 and 3.
- Line 5: line 1 minus line 4. If the result is positive, that balance must accompany the form.
Line 1 is the number that drives everything else. Maryland law does not extend the time to pay, so any shortfall between what you pay with the extension and what you ultimately owe accrues interest from the original due date.3Comptroller of Maryland. Application for Extension to File Corporation Income Tax Return A small overpayment that generates a refund later is cheaper than seven months of interest on an underpayment.
How to Submit the Form
Your filing method depends on whether line 5 shows a balance and whether this is your corporation’s first Maryland filing.
When Line 5 Is Zero
Corporations that have previously filed a Maryland Form 500 can skip the paper form entirely. File the extension online through the Comptroller’s business services portal, by telefile at 410-260-7829 in central Maryland or 1-800-260-3664 elsewhere, or through approved tax software using the Modernized Electronic Filing (MeF) method.4Comptroller of Maryland. Application for Extension to File Corporation Income Tax Return If you file electronically, keep the completed paper form in your records and do not mail it.
First-time filers are the exception. If your corporation has never filed a Maryland Form 500 before, you must mail the paper Form 500E even when no tax is due.3Comptroller of Maryland. Application for Extension to File Corporation Income Tax Return
When Line 5 Shows a Balance
You have two electronic options for paying: register for Electronic Funds Transfer through the Comptroller’s office, or file through approved MeF software. Corporations making payments of $10,000 or more are required to use one of these electronic methods.4Comptroller of Maryland. Application for Extension to File Corporation Income Tax Return Below that threshold, you can mail the paper form with a check or money order payable to “Comptroller of Maryland.”
Mailing Address
Paper filings go to:3Comptroller of Maryland. Application for Extension to File Corporation Income Tax Return
Comptroller of Maryland
Revenue Administration Division
110 Carroll Street
Annapolis, MD 21411-0001
Use a mailing method that generates a postmark or delivery confirmation. That date is your proof of timely filing if a question comes up later.
How Long the Extension Lasts
Maryland Tax-General § 10-823 authorizes the Comptroller to grant corporations an extension of up to seven months from the original due date.5Maryland General Assembly. Maryland Code Tax-General 10-823 – Extensions for Filing Returns Filing Form 500E on time triggers that extension automatically. There is no approval letter to wait for.3Comptroller of Maryland. Application for Extension to File Corporation Income Tax Return For a calendar-year corporation with an April 15 original due date, the extended deadline is November 15.
Interest and Penalties on Unpaid Tax
The extension never postpones the payment deadline. Maryland Tax-General § 13-601 directs the Comptroller to charge interest on unpaid tax from the original due date regardless of any extension.6Maryland General Assembly. Maryland Code Tax-General 13-601 The 2025 annual interest rate was 11.4825%; the Comptroller had not yet published the 2026 rate at the time of writing.
On top of interest, the Comptroller can assess a penalty of up to 10% of unpaid tax for failure to pay on time.7Maryland Comptroller of the Treasury. Tax Guidance – Penalty and Interest Charges Penalty charges for late payments can reach as high as 25% depending on the tax type. Estimate your liability carefully on line 1, and pay as much as you can by the original due date.
Quarterly Estimated Payments Factor In
Corporations expecting Maryland tax to exceed $1,000 for the year must make quarterly estimated payments on the 15th of the 4th, 6th, 9th, and 12th months of the tax year.8Comptroller of Maryland. Underpayment of Estimated Income Tax by Corporations and Pass-Through Entities – Form 500UP Those payments go on line 2 of Form 500E. The Comptroller assesses separate interest on underpayment of estimated tax, which you avoid if your total estimated payments equal at least 90% of the current year’s tax or 110% of the prior year’s tax, whichever is less.9Maryland Division of State Documents. COMAR 03.04.07.03 – Filing of Returns and Payment of Tax If you have been paying quarterly all year, you may find little or nothing is owed with the extension, which opens up the easier electronic filing options.
Pass-Through Entities Use a Different Form
S-corporations, partnerships, LLCs, and business trusts that file Maryland Form 510 or Form 511 do not use Form 500E. They file Form 510/511E instead.10Comptroller of Maryland. Application for Extension to File Pass-Through Entity Income Tax Return S-corporations receive up to seven months; other pass-through entities receive up to six.