What to Do If You Miss Today's Tax Deadline

If it's clear you're not going to pass the midnight finish line on for today's "Tax Day," don't panic.

You have options.

Though about 100 million individuals filed their taxes as of April 3, according to the IRS, millions of Americans still miss the April 15 filing deadline for their federal taxes. You could ask for more time, but it won't be without consequences.

If you can't file your return, you still need to file an extension today.

"But the most important thing to remember is that an extension is only an extension to file, not an extension to pay," Richard Gartland, H&R Black senior tax advisor said.

Not paying on time could be costly because you'll be subject to both interest and penalties.

Gartland said the interest can be "reasonable," but the penalties can add up to 25 percent of the tax bill. But, if you are owed a refund, or expect to break even, you do not need to send a payment.

What if you still can't get it together today? The IRS says you should still file as soon as possible to keep those extra costs to a minimum.

There are several ways to file an extension, including through the Free File link on IRS.gov, or by designating an extension payment via one of the IRS e-payment methods, including IRS Direct Pay. Or, taxpayers can file Form 4868.