NEW YORK (MainStreet) – Take a quick look at the calendar, taxpayer: If you haven't filed yet, you're just about out of options.

While the rest of the haughty taxpaying world firmly believes that everybody files by the Internal Revenue Service's tax deadline at the end of the day today, there is still a robust portion of the population racing to file their taxes at the last minute. Jonathan Medows, a New York certified public accountant who tailors his service specifically to freelancers, hears from a lot of them around this time of year, his clients among them.

You have a lot of people in this situation,” Medows says. “I get a lot of these last-minute calls, but unfortunately I'm really only handling the current clients and taking care of them because there are always a lot of last-minute issues that come up — making sure their stuff is e-filed, making sure extensions our e-filed.”

Frankly, if you've waited this long, your options are somewhat limited. Medows, who's been fielding 10 to 20 calls a day from procrastinators since early August, notes that most accountants are booked and that late e-filers will have to take their chances with tax preparation services — which are also swamped — or tax software. Beyond that, there is exactly one good option left on the table.

"If you wake up on April 15 with nothing done, there is one major step you can still take that day: Electronically file Tax Form 4868 to request an automatic filing extension,” says Eric Meermann, a certified financial planner and enrolled agent with Palisades Hudson Financial Group in Scarsdale, N.Y. “This action secures you six months of additional time to prepare and file your return without any late-filing penalties.”

Don't shrug off those penalties, either. The federal penalty for failure to file starts at 5% per month and tops out at 25% of taxes owed. And Medows points out that state penalties can be far worse. Failure to file in New York State, for example, comes with a whopping 7%-per-month penalty.

If you don't have to pay and you have a refund coming, you're set until April. If you owe taxes, however, that extension doesn't change the date your tax payment is due. You're still going to want to send something in by April 15, otherwise you're subject to a 0.5% to 1% monthly federal penalty for late payment, which also caps out at 25% of your unpaid taxes. The monthly federal penalty for failure to file and failure to pay is capped at 5%, but still isn't ideal to incur both with state penalties on top of them.

“No. 1: File an extension,” Medows says. “No. 2: Do you think you owe? Find an online calculator, pay what you think you owe now to the extent that you can.”

As Meermann notes, if you pay at least 90% of your taxes owed when you file an extension request, there's a good chance the failure-to-pay penalty may be waived. Medows insists on double-checking information such as date of birth and Social Security numbers before mailing in payment, and highly recommends getting a receipt or email confirmation for any payment sent. Considering that many late filers have waited this long specifically because they don't have the money, though, Medows makes this recommendation:

”Triage appropriately.”

If you're filing in New York State, for instance, the 5% federal penalty and 7% state penalty for failure to file are a lot worse than the 0.5% levy for failure to pay. Take the hit and use those six months to build your resources. Also, if you're self-employed and have your first quarterly tax payment of 2015 due on April 15, you'll again have to consider your priorities.

If you have to choose between the two, it's a tough choice, but I would go with the current-year obligations given the interest rate and take care of 2014 if you can,” Medows says.

As for how quickly you should file if you've received an extension, there's a fine line between hurrying up and waiting. Meadow notes that a six-month extension provides ample time for a taxpayer to go over their 2014 information and find breaks that he or she may have missed. It's something he has just a bit of personal experience with.

“I file an extension,” he says. “I'm like the shoemaker: I file an extension because I have a lot of personal stuff and I don't want to miss deductions, but I make sure that when I file an extension that I've paid up all my projected estimated liabilities so I don't incur any subsequent interest for filing after the deadline.”

Don't just blow through the April 15 deadline or your extension deadline and expect to be OK, though. Meermann points out that those who filed their returns more than 60 days after the deadline (or the extended deadline) are also subject to a minimum penalty of $135 or 100% of the unpaid tax, whichever is less. To the worst of the procrastinators out there, Meermann suggests that the sooner you stop ignoring the problem, the better off you'll be.

“If you can't afford to pay your whole tax bill, the IRS generally works with taxpayers to set up installment payment plans or other compromises if necessary,” he says. “While lateness is never the best-case scenario, the sooner you get your taxes done, the less your tardiness will cost.”

— Written by Jason Notte in Portland, Ore., for MainStreet

To follow the writer on Twitter, go to http://twitter.com/notteham.

This article is commentary by an independent contributor. At the time of publication, the author held TK positions in the stocks mentioned.