Returns for entities taxed as corporations under Subchapter C or Subchapter S that have a calendar year must file by March 17, 2014 (the 15th is on Saturday) or request an extension. The extension is an extension of time to file NOT an extension of time to pay.
Penalties for “S” corporations start at $195 per owner per month or part of a month that the return is late. So if you file March 18, 2014 – one day late – then the “S” corporation owes $195 times the number of owners. Some small “S” corporations can get the penalty waived but it is best to file an extension if the “S” corporation cannot file by March 17, 2014.
Penalties for “C” corporations are 5% of the unpaid tax per month or part of a month late. The maximum penalty is 25%. “C” corporations also pay interest on tax not paid by the first due date.
Both types of corporations file Form 7004 (PDF) to request a federal extension. Most, if not all, states also require an extension form and charge penalties for late filing. For NC the extension form is CD-419 for both “S” and “C” corporations. We typically file them when we file the federal extension but the NC extensions are not due until April 15, 2014, which is the same due date for the NC corporate returns for calendar year corporate taxpayers.