We all have regrets — money regrets, that is. But, like all mistakes, we wouldn't be who — or where — we are today without them. In our "Money Fails" series, real people share how they bounced back from financial slip-ups, and what they learned along the way.

Here, one woman explains how missing an error on a previous tax return is costing her — in time, money and headaches — today.

Logically, I know the IRS exists. That said, it always felt about as real as the mob to me; the likelihood of interaction was so low that the agency seemed like a fictional entity in my mind.

So imagine my surprise when I came home from work a few months ago to a very formal, very real notice from the IRS stating that I owed nearly $3,000 from my 2015 tax return. The possibility that I was being audited by the IRS seemed so absurd that I spent most of the night Googling “tax scams” and texting my accountant friends for help.

The form I was issued, a CP2000, indicated that I underreported my taxable wages in 2015. When it came time to file my taxes that year, I had a pile of W-2 forms from two full-time jobs, plus a handful of 1099s from various freelance employers.

In the deluge of paperwork, I didn’t pause to think about the numbers I was mindlessly entering into TurboTax while filing. If I had bothered to carefully review my W-2s, I would have realized that my former employer had messed up in a big way.

Instead, I didn’t blink at the (outrageously low) number that represented my wage on the form. That amount should have immediately stood out as incorrect, but between the stress of filing taxes and a short attention span for anything math-related, I didn’t catch it.

Here’s exactly how much my IRS audit is costing me, 3 years later:

  • Total taxable wages owed to the IRS: $2,311
  • Penalty for underreporting my income in 2015: $462
  • Interest that has been accumulating at 4% since 2016 while I remained blissfully unaware that anything was wrong: $172
  • A PDF download of my 2015 W-2 from Equifax (hot tip: it’s a good idea to keep hard copies of your recent tax returns on hand): $10
  • Sending a fax at Staples to reach my former employer for clarification, because they don’t accept phone calls for tax-related concerns, apparently: $7.48
  • Total: $2,962.48

I've learned that if you ever get audited, the best course of action isn’t to try and figure it out on your own. Time is money, and the interest rate is ticking up as you take the time to sort out the issue. Your best bet is to get in touch with a certified public accountant (CPA), who can help you navigate the often tricky waters of owing money to the federal government.

I asked Caitlyn Rodrigues, CPA, MSA, what you should do if you get audited and, you know, how to avoid getting there in the first place.

What’s the first thing you should do when you find out you’ve been audited?

Make sure you’re actually being audited by the IRS. You won’t receive an email, phone call or text message to initiate an audit from the IRS. Instead, you’ll receive a letter on their official IRS letterhead that details exactly which tax return they’re looking to audit.

The IRS can review any of your tax returns from the last three years. Once you’ve determined you’re being audited, you need to determine exactly what the IRS is disputing on the return they’ve selected.

Then, compile all of the tax documents related to that return and go through them to make sure the information was entered into the tax return correctly. If you're unable to do this on your own, call a CPA or tax professional to see if they can check the accuracy of the return for you.

What if you don’t agree with the proposed changes on the audit?

You have the option to either agree or disagree with the information that’s stated on the IRS form. If you ultimately don’t agree, there are instructions on your form that will tell you what to do. However, it’s still best to contact a CPA or tax professional to help you deal with IRS auditors. An individual shouldn’t have to deal with the IRS alone. A CPA or tax professional will speak to the IRS on your behalf and ensure that the only information being provided to the IRS auditors is the information that they are requesting.

How can you avoid getting audited in the first place?

Review all of your tax documents (W-2s, 1099s, 1098s, 1098Es, 1099-INTs and so on) to make sure everything is accurate when you receive them. Confirm that you received a tax document from anyone who provided you with any type of income throughout the year. If you think you should have received a tax document but didn’t, reach out to resolve any discrepancies between your records and theirs. If you don’t do this, they could report taxable wages paid to you, and you won’t report the same taxable wages on your return.

Make sure the form actually belongs to you by double-checking the name and social security number listed. Next, make sure the amounts noted on your form appear to be reasonable based on your own records. Tax return filing websites (like TurboTax and H&R Block) are great tools for individuals to complete and file their tax returns independently, but the downside is that these platforms are only as effective as the information the user is entering.

This publication is not intended as legal or tax advice. Taxpayers should seek advice based on their particular circumstances from an independent tax advisor.