April 15 falls on a Saturday this year — giving taxpayers until midnight on April 17, to get their returns mailed. For procrastinators this means a few extra hours, but for accountants it only adds up to another weekend of work.

Carol Baumgartner, an accountant with Marie Messner, CPA, PC, says that although taxpayers have a few extra days to get their returns into the mail, if they owe money to the Internal Revenue Service (IRS), that money must still be postmarked by Monday unless an extension is filed.

"If your return is not postmarked by the 17th, then you may be charged with a non-filing penalty," says Baumgartner. "And once you get on the IRS’ list for not filing, even if it is a mistake, then it seems like you never get off — you don’t want to get on that list," she said.

Baumgartner said that in the 13 years that she has been an accountant, she has never had an extension denied. If returns can not be filed by Monday, taxpayers should file form 4686, Application for Automatic Extension of Time to File U.S. Individual Income Tax Returns, by April 17. This is an extension to file paperwork, not an extension to pay the tax owed.

If taxpayers are unable to pay by April 17, then form 9465 [Installment Agreement Request] should be attached to their returns. If approved, the payment agreement costs $43 to set up and $21 for any additional changes.

"We can sit down with individuals and help them fill out an extension form or they can pick one up at our office and fill it out on their own," said Baumgartner.

Individuals who are eligible for Advanced Earned Income Tax credit because a qualifying child lives with them may be able to get part of that credit paid to them in advance. Form W-5, Earned Income Credit Advanced Payment Certificate, should be filed and an employer will include part of the credit in regular pay checks.

The Internal Revenue Service reminds citizens to make sure that all appropriate names are listed on returns, all social security numbers are included, math has been checked, returns have been signed, W-2s and Form 1099 are attached as required and the appropriate postage has been placed on the envelope.