It turns out 60% of us seek the help of some kind of is actually helping you and not putting your money at more risk? Abc's steve osunsami on how to avoid a huge, costly mistake. Reporter: The... See More
It turns out 60% of us seek the help of some kind of is actually helping you and not putting your money at more risk? Abc's steve osunsami on how to avoid a huge, costly mistake. Reporter: The commercials are pretty funny. I thought you were a tax expert. Reporter: That the guy you're trusting to complete your taxes today could be working under your sink tomorrow. Today, I'm a master plumber. Reporter: Well, the government says that thousands of families, like debbie and keith sleight, aren't laughing. Oh, my god, we cried for days. Very frustrating. Reporter: For three years, they used one of those seasonal office tax preparers to file their taxes. They were newly married, using extra money to send care packages to soldiers overseas, and the tax preparers were recommended by friends who had gotten big refunds. I thought what he was doing was right. Reporter: Then, they were hit with an audit. Your federal return has been selected for examination. Reporter: It turns out the government says their tax preparer had made up several thousand dollars worth of deductions. So, almost $9,000 in deductions you couldn't claim. Right. Reporter: The law says that taxpayers are always responsible no matter who fills out the forms, so now, they owe nearly 16 grand in back taxes. The tax prepare is being sued by the government. Brothers larry and andy heath ran two separate businesses. The irs says that 94% of tax returns they filed over five years when they worked together, required adjustments and contained patently false information, and it's the families that have to pay the money back, plus interested and sometimes penalties, too. I'm looking for larry heath. We tried getting answers from the brothers, neither of whom are accountants. Larry heath and his lawyer refused to talk. We did reach andy heath who said he's estranged from his brother. And in court papers repeatedly denies knowingly filing and false returns. Jtsds if the -- if the first thing they start talking about is guaranteeing you a refund, that's something you should be concerned about. Reporter: He says there are clear red flags. If you're asked to sign a form before it's completed, or they only show you the bottom line and skip the details, you should get up and walk away. We kept calling him. Nothing. Reporter: And now, they're stuck with monthly payments to both the irs and the state of georgia for five years. Steve osunsami, abc news, atlanta.
This transcript has been automatically generated and may not be 100% accurate.