Tax Day 2018: How to file an extension and more last-minute tips

Tuesday's the day: Taxes are due.

Nearly 25 percent of people who filed on time last year waited until the last two weeks before the deadline, according to the Internal Revenue Service.

If you haven't filed yet, the question likely at the top of your mind is how to file an extension. Before you decide to do that, though, you should know that if you owe money, an extension to file is not an extension to pay.

"The best advice is pay what you can as soon as you can and set up a payment plan to pay off the rest of it," Kathy Pickering of H&R Block explained to ABC. "If you're worried about owing money, file your taxes, even if you can't pay, and work out that payment plan with the IRS."

But if you know you're not going to file by the deadline, make sure you ask for an extension rather than ignoring it.

"The 'failure to file' penalty is 10 times more than the 'failure to pay' penalty," Pickering said.

The IRS will charge you both late payment penalties and interest on your taxes, she said.

If the government owes you money, however, the only penalty for missing the deadline is that you won't get your refund as soon. If you fail to file your taxes within three years of the original deadline, you won't get your refund at all.

If you want to file an extension, fill out and return this form.