Corporation Income Tax Due Dates and Extensions

Form 500 must be filed by the 15th day of the third month following the close of the taxable year or period, or by the original due date required for filing the federal return.

Corporations and organizations that are allowed later due dates for federal returns under the Internal Revenue Code are allowed the same due date for Maryland income tax returns.

Extension of Time to File

If you are unable to file Form 500 by the due date, see Form 500E, Application for Extension of Time to File Corporation Income Tax Return, for instructions on how to file an extension. Maryland law provides for an extension of time to file, but in no case can an extension be granted for more than seven months beyond the original due date.

A seven-month extension can be granted for corporations using Form 500E and S corporations using Form 510E, Application for Extension of Time to File Pass-Through Entity Income Tax Return. A six-month extension can be granted for partnerships, limited liability companies and business trusts using Form 510E.

A request for an extension of time to file will be automatically granted and will not be acknowledged, provided that:

The application is properly filed and submitted by the 15th day of the third month following the close of the tax year or period, or by the original due date required for filing of the federal return; and
Full payment of any balance due is submitted with the application.

The application extends only the time allowed to file the annual income tax return and not the time allowed to pay the tax.

For more information about corporation income tax extensions, see Administrative Release No. 4, Extension of Time for Filing Maryland Individual, Corporation, Partnership, Limited Liability Company, Fiduciary Income Tax Returns, and Estate Tax Returns.