(AP) — Amy Baxter’s business took off after she appeared on “Shark Tank” with her device that blocks pain from injections — orders flowed in and she bulked up her inventory.

But after sales hit a temporary speed bump, Baxter learned there was no tax break for the merchandise she hadn’t sold yet.

“I remember sitting at my parents’ house, realizing there was no way out of this,” says Baxter, a pediatric emergency physician whose company, Pain Care Labs, sells Buzzy, a device that uses a combination of cold and vibration to reduce injection discomfort. “I was going to have the worst debt of my business.”

Small business owners can be devastated when upon learning they owe the government thousands, or even tens of thousands, of dollars. It can happen at any stage of a company’s life, and can be the result of poor planning or not getting advice from an experienced tax adviser. But changes in tax laws can also leave owners with unexpectedly large bills, and tax advisers warn it can happen to more companies this year because of the many unknowns about the new tax law.

Baxter appeared on the TV show “Shark Tank” in 2014 with Buzzy and had her best year since starting the Atlanta-based business in 2006. She significantly increased her inventory, but sales to pharmacies didn’t take off as expected. Baxter thought she could write off the unsold inventory but learned from a fellow entrepreneur that the IRS doesn’t consider inventory to be a cost until it is sold or disposed of.

“Our tax bill was so huge I had to liquidate my life insurance policy to pay it, and didn’t move the inventory until two years later,” Baxter says.

Baxter ran into problems because her long-time accountant’s specialty was working with physicians, not manufacturers; without the right advice, Baxter couldn’t plan for a big tax bill.

Unfamiliarity with the tax code has historically been a common problem leading to huge tax bills, and it’s one that’s likely to be more pervasive this year as owners and practitioners try to understand the new law, says Scott Berger, an accountant with Kaufman Rossin in Boca Raton, Florida. There’s still confusion in particular about a new 20 percent deduction that’s available to some sole proprietors, partners and owners of what are called S corporations.

But no matter how big their tax bills, owners need to file their returns on time and figure out how to pay their debt to the government.

“Many clients say, ‘I don’t have the money and I’m not going to file.’ That’s the worst scenario,” says Berger. The penalties for not filing can run as high as 25 percent of unpaid taxes.

Predicting how strong business is going to be over the course of a year can be difficult, and owners who aren’t proactive about setting aside money for taxes can get quite a shock. Bobby Kittleberger was taken by surprise by how well his online magazine, Guitar Chalk, did in 2017 after breaking even in 2016.

“We made a ton of money late in the year but also didn’t manage well enough to pay the IRS,” Kittleberger says. One problem: He hadn’t hired an accountant who could have talked to him about planning.

“I honestly did not know what to expect,” he says.

Kittleberger ended up owing the government $20,000 and had to get an installment payment plan with the IRS. He finished paying off the bill in January.

Keeping good financial records is another way to help avoid a tax crisis, says Miguel Farra, a tax attorney and accountant with MBAF in Miami.

“Good books and records are like a dashboard on your car. You need to know how fast you’re driving and how much gas you have and whether you’re overheating,” Farra says.

Startup owners can run into tax problems because they’re trying to save money. Many try to handle tax planning and returns themselves but don’t understand the complexities of tax laws. Those owners are in danger of spending more than they save, Farra says. If owners underpay their taxes or need an installment payment plan, they’ll have interest and penalty charges that may cost more than a tax adviser’s fees.

Some owners hire bookkeepers or accountants based on one person’s recommendation and find out the hard way they’re dealing with inexperience or incompetence.

When Phil La Duke started a consulting business in 1992, he hired a bookkeeper at a colleague’s suggestion, and trusted her to make his quarterly estimated tax payments and compile his return. But she disagreed with the amount he wanted to pay the government and, when it came to tax filing season, became uncommunicative.

When he got his return, La Duke discovered he owed the government $10,000.

“I trusted her blindly, based on a recommendation,” La Duke says. “I could have asked her for references, but I didn’t.”

La Duke was able to set up a payment plan with the IRS and got his tax bill reduced because of mistakes the bookkeeper had made. But it took him two years to pay the government back, and La Duke felt so traumatized he closed his business and went back to work full time. It took him 20 years before he felt secure enough to start another consulting firm.