It’s crunch time for procrastinators, with the April 17 deadline looming for filing (and paying) state and federal income taxes.

If you’ve already filed and you know whether you owe or are due a refund, there’s an important step that you still need to take. But first, here are some tips for the last-minute filers.

Still working on your taxes? If you’re preparing your own taxes, hopefully you’re using tax preparation software, which can address many questions and eliminate math errors.

If your adjusted gross income is $57,000 or less, you can get no-cost access to brand-name tax software through the IRS’ Free File program on IRS.gov, and then file your taxes electronically.

The IRS does provide assistance with tax questions by phone or in person, but at this late date, expect busy signals and long waits. For telephone assistance, call 800-829-1040 weekdays 7 a.m.-7 p.m. In the Charleston area, the IRS Taxpayer Assistance Center is at 1 Poston Road, off Sam Rittenberg Boulevard in West Ashley. The phone number is 566-0209, and extended office hours are 7:30 a.m.-5:30 p.m. through Tuesday.

The IRS also has produced videos aimed at answering common questions. They are available on YouTube.com and on the IRS’s phone app, IRS2Go.

Can’t get finished on time? If you just can’t get your federal taxes finished on time, you can get an automatic six-month extension. An extension can be electronically requested through Free File on irs.gov using Form 4868, which gives taxpayers until Oct. 15 to file a return.

The catch is, while you can get an extension, you would have to estimate your tax liability and pay any amount due by April 17. An extension eliminates late-filing penalties.

South Carolina returns also are due April 17, but people who file and pay electronically have until May 1. If you need more time, you’ll need to file for an extension by April 17 and pay the balance due online at sctax.org, or file the paper form SC4868.

Can’t pay what you owe? If you owe the federal government taxes for 2011 that you can’t pay right now, go ahead and file your return in order to avoid penalties for late filing or failure to file. Then you can request an extension of time to pay, or make payment arrangements such as an installment plan.

For most of the people who were unemployed for at least 30 consecutive days in 2011 or this year through April 17, and most self-employed people whose income dropped by at least 25 percent, the IRS will allow an extension without failure-to-pay penalties until Oct. 15.

The extension must be applied for (form 1127A), interest will be due on amounts owed at a yearly interest rate of 3 percent, and the penalty-free extension is available only to those earning less than $100,000 (filing single) or $200,000 (filing jointly).

For South Carolina taxes, the Department of Revenue recommends borrowing money to pay the tax bill, and only seeking an installment agreement if there are no other options. An installment agreement requires a 10 percent down payment and will not stop the liability from becoming a tax lien.

Waiting for a refund? If you’ve already filed tax returns and are wondering when a refund might arrive, you can check the status of a federal refund on the IRS website. Look for the “Where’s my refund?” logo and be prepared to enter your Social Security number, filing status and the refund amount from your tax form.

The IRS says refunds can be tracked 72 hours after filing electronically or four weeks after filing a paper return. Most refunds are issued 10 to 21 days after filing.

For South Carolina refunds, visit sctax.org and look for the “Refund status” option under “Quick links.”

Take the next step: If you have filed your tax returns and know whether you owe money or are due a refund, then you have the information you need to adjust your tax withholding or estimated payments for next year.

If you’re getting a big refund, unless it’s due to the Earning Income Tax Credit, your refund means you gave the government a tax-free loan during 2011. Adjust your withholding (or estimated payments if self-employed), and you’ll get larger paychecks now and a smaller refund next year.

If you’re getting a big tax bill, you’ll want to see if you are having enough withheld, so that you don’t end up with another big surprise next April. The self-employed face penalties if their estimated payments are too low.

Reach David Slade at 937-5552 or Twitter @DSladeNews.