One of the biggest tax mistakes people make is not filing their tax return because they owe money. By not filing, the IRS can assess a ‘Failure to File’ penalty and they could also calculate your taxes for you, which most likely would not include any deductions or credits you may be entitled to. You may also be due a refund for any withholding deducted from your paycheck, or eligible to receive Earned Income Credit.
If you owe, and cannot afford to pay the entire amount due, pay as much as you can. You may be able to work with the IRS to pay the unpaid balance or you may be able to get an Installment Agreement with the IRS, allowing you to make payments.
Please keep in mind, filing an extension is an extension to file your tax returns, not an extension to pay any taxes owed. You are required to estimate the amount of tax you owe and pay it by the due date, which is April 18th, 2016 for the 2015 tax year. If the estimate you pay is not reasonable, the IRS could void your extension, and charge penalties and interest.