Big profits in 2013?  Make purchases now, rather than next year.

If you’re running your own business, then finding time to keep up on money-saving tax strategies can be a challenge — one that’s complicated by the fact that tax laws are constantly changing.

Here are three simple tax strategies to keep in mind as Dec. 31 approaches.

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1. Run the numbers

The best thing you can do before year-end is get your accounting up-to-date and figure out whether you have a profit or loss, said Eva Rosenberg, an enrolled agent who publishes TaxMama.com and is a contributing writer for MarketWatch.

It’s best to do that now, while you still have time to make adjustments. Otherwise, “there’s no way to plan,” Rosenberg said. “I’ve seen too many people come to me and say, ‘Look, I have a $100,000 loss for the year’” — only to discover that the business owner has failed to correctly account for some item, such as inventory.

Once it’s correctly entered, “They may have a $200,000 profit and owe tax,” she said. “It’s too late to do anything about it by the time they come in on April 13.”

If you haven’t hired a tax professional, one option to assess your tax situation is to log into one of the tax-preparation websites, such as TurboTax, H&R Block or one of the others, to run the numbers.

You’re using prior-year software, but it’s better than the tax forecasting tools that most of the companies offer, Rosenberg said.

“Put numbers in relating to your current year’s income and expenses so you actually see what the real potential taxes are including the effect of the alternative minimum tax and self-employment taxes that usually are overlooked in those quickie calculators,” Rosenberg said.

Self-employment taxes can be a big surprise, she said. “You’re thinking, ‘My business profit is $30,000 but my itemized deductions are $30,000 or so, so no income tax.’ But then you get hit with self-employment taxes on $30,000. That becomes a huge shock to people.”

2. Take advantage of expiring provisions

There’s no way to predict how the U.S. Congress will act. Often, expiring tax provisions are extended for another year or more, but it’s hard to know when or if that will happen. So it makes sense to assess whether any business decisions you make can be tailored to take advantage of tax breaks.

For example, the so-called Section 179 expense deduction currently allows small businesses to write off the cost of certain types of equipment purchases — both new and used — up to $500,000. Come January, that maximum is slated to drop to $25,000.

Congress tends to extend that tax break, “but you never know, so if you’re looking at major equipment expenses it might be good to get that in place before year-end, when you know that $500,000 is available,” said Mark Luscombe, principal tax analyst with CCH, a Riverwoods, Ill.-based tax publisher and unit of Wolters Kluwer.

Similarly, there’s currently a 50% bonus depreciation tax break that allows business owners to deduct up to 50% of the cost of certain acquisitions — and there’s no dollar limit, Luscombe said. The property must be new, and must be placed in service by Dec. 31.

But you need to act fast on such purchases. That tax break is also set to expire at the end of the year “and potentially might not be renewed,” Luscombe said.

Rosenberg agreed that business owners who are looking at a big profit this year should consider making purchases now, rather than next year.

“Buy up all the things that you’re going to need for next year and put them into service before the end of the year,” Rosenberg said. “This is a good time to buy the next computer, the next copier and so forth, and make sure you take it out of the box and use it before Dec. 31.”

Another expiring provision to consider — depending on your business situation — is the Work Opportunity tax credit, which is available to business owners who hire veterans, disabled people and people in other select groups. The tax credit generally is worth up to 40% of the first $6,000 of qualified wages paid to a new hire who falls into one of the targeted groups. (The precise amount of the credit varies based on a number of factors.)         Read more about the credit on the U.S. Labor Department website.

“That tax credit also currently expires at the end of this year,” Luscombe said. “You’d have to hire someone before 2014, if it doesn’t get renewed, to be eligible for the credit.”

3. Assess your situation under the Affordable Care Act

While small employers — those with fewer than 50 employees — aren’t subject to penalties if they don’t provide insurance to their workers, even small employers may be eligible for a tax credit for offering coverage, Luscombe said, noting that the credit has been available since 2010.  Read more about the tax credit on IRS.gov.

Separately, some small businesses may be required to notify their employees about the health insurance available to them through the new health-care exchanges. Generally, this requirement is limited to businesses that generate at least $500,000 in annual dollar volume.

For more details on the rules,  see this Labor Department page.

Check out this Small Business Administration for more information, including dates for upcoming webinars on  how the health law affects businesses.

Source:  MarketWatch.  Author, Andrea Coombes personal-finance writer and editor in San Francisco. She’s on Twitter @andreacoombes.