It’s a chilling thought: What if you complete your tax return and discover that you owe the government much more than your small business can afford?

If you find yourself in this predicament, you have two problems. First, you have to find a way to pay the IRS. Second, you have to figure out what’s gone wrong in your business – especially with your cash flow – and fix it.

Perhaps the most important thing to remember if you can’t pay your taxes is that you must file your return anyway. Filing late likely will cost you 5 percent of the amount of tax you owe per month that your tax goes unpaid.

“It’s important to come clean and acknowledge your debt with the IRS, declaring the tax you owe even if you don’t pay,” said Robert Pesce, a partner with Marcum &Kliegman LLP, a New York-based accounting firm. That way, “all you get stuck with is the late payment fees, which are not outrageous.”

It’s even possible to get extensions of the April 15 filing deadline and not pay – as long as you’re upfront with the government about the amount you owe. With two extensions possible, shifting the filing deadline until Oct. 15 means “we work with clients to be sure they have enough money” at that point, Pesce said.

If you don’t have the cash on Oct. 15, you have other options, but there’s no getting around the fact that most will impose an additional financial burden.

Hopefully, you have some personal alternatives such as a home equity line of credit or other loan, an IRA or 401(k) you can draw on, perhaps even a loan from a family member. They all come at a price – an extra monthly payment or, if you’re hitting up your retirement account, possible penalties and higher taxes for the current year.

This can be particularly onerous for a business that’s losing money. “It becomes like a snowball that keeps rolling and rolling and rolling,” said accountant Jeffrey Berdahl of the firm Beard Miller Co. in Allentown, Pa.

You also can request an installment payment agreement with the IRS, although accountants and the agency will tell you that you’re likely to get a better deal on interest elsewhere. (Pesce called the IRS “the lender of last resort.”) The IRS Web site, www.irs.gov, advises: “A more favorable solution to resolve the debt would be to obtain a loan from a bank or other financial institution, or pay taxes using a charge card.”

If you are thinking of an IRS installment plan, you’ll need to attach Form 9465, Installment Agreement Request, to the front of your return. Form 9465 does not request any detailed financial information, but Berdahl warned that if you owe a substantial amount, the IRS might ask to see financial documents.

“They want to know that there’s some ability or net worth to pay it back,” Berdahl said.

In extreme cases, a taxpayer can ask the IRS for an offer in compromise, which recognizes the fact that the entire tax bill is unlikely to ever be collected. Chances are your business is in tatters by that point. Form 656, Offer in Compromise, says “the taxpayer must not be able to pay the taxes in full either by liquidating assets or through current installment agreement guidelines.”

Some business owners might think about bringing in an investor who would be willing to supply cash to pay the bill. But you’re likely to be hard-pressed to find someone to help, Berdahl said, adding that “any partner coming in would want to know why there’s a cash-flow issue.”

Clearly, any business that can’t pay its tax bill on April 15 – and probably also can’t make the estimated payment due that day – needs to look at its cash flow to determine what the problem is.

“You’re overspending or overleveraged,” Berdahl said. “You have to stop the bleeding.”

If you’re not working with an accountant, you should be. Both Pesce and Berdahl noted that when their clients come in for year-end tax consultations, they can find out if they’re facing a possible bill in April.

By working with an accountant, you can also figure out a way to set aside tax money on an ongoing basis and avoid this problem in the future.

If an inability to pay your taxes is a symptom of your business being in serious trouble, that’s also something that you have to deal with – before your company collapses.

Building Small Business is a weekly column on the topic by the Associated Press.