A “debt collector” call can arrive at any time for just about anyone. Even if you’ve never missed a payment on a bill. There’s only one way to protect yourself: Know what questions to ask.

Debt collector telemarketing scams are incredibly persistent because they work. “Debt collectors” can sound scary, and when they catch consumers at the right time, they can quickly trick people into paying up before they realize what’s happened.

The IRS has issued near-continuous warnings about the taxman flavor of this scam for years.

“Taxpayers across the nation face a deluge of these aggressive phone scams,” IRS Commissioner John Koskinen said earlier this year.

These scams work because fake debt collectors have a huge advantage over other kinds of telemarketing scam callers: You really can’t just hang upon them. Even if you are sure you’ve paid all your bills and taxes on time, a call about debt could be an important warning signal that your identity has been stolen or some other foul play is at work. So it’s unwise to simply hang up on a debt collector. You should stay on the line long enough to get answers to the questions posed below.

(This story first appeared on Credit.com. Read it there.)

Of course, many fake debt collectors aren’t randomly dialing victims. They are working off lists that make it more likely they hit a decent “mark.” Online payday loan lead generators are known for selling consumer’s personal information to scammers, even if the consumers don’t ultimately take out loans. Why? People who look up payday lending information are much more likely to be in some kind of financial trouble and ripe for the taking. Similarly, consumers with old debts that are no longer collectible (every state has a different statute of limitations on debt collection) often receive phone calls from collectors hoping they can talk consumers into paying up anyway.

Whatever the circumstance, here are the questions to ask anyone who calls claiming to be a debt collector. They’ll help you sniff out potential scammers.

PART 1: ESTABLISH IDENTITY

1. Who are you? Who do you represent? What is your direct telephone number? What is the address?

If the caller is at all squeamish about sharing his or her name and full contact information, that’s the biggest red flag of all. Don’t continue any conversation with anyone who won’t answer these questions. Do repeat them several times, as any contact information you can get – even partial information – might be useful to you in any legal action later on (such as a Do Not Call lawsuit). You can learn more about your debt collection rights here.

2. What is your professional license information?

Many states require debt collectors to be licensed. This is the easiest way to verify a collector’s identity. Take the information provided, and double-check it with your state’s authorities online – don’t just take the caller’s word for it.

3. What is the name and address of the debtor you are trying to reach?

That might sound obvious, but it’s not always the case. A “cold call” scammer wouldn’t have this information, for example.

4. Can I call you back in a few minutes?

After you get this information, it’s probably a good idea to hang up and call back. This will verify that the contact information is accurate, and will often trip up scammers who are lying about their location – if the call is coming from overseas, for example, but spoofed to appear local. It also gives you a moment to stop and collect your thoughts.

PART 2: ESTABLISH THE FINANCIALS

5. What is the amount of the alleged debt and who is the current creditor?

The current creditor should be the party calling. Be sure to ask for specifics, such as: What was the original amount, and what is the breakdown of other fees that have been added?

6. How can you seek verification and validation of the debt?

Debt collectors do not have to provide debt specifics during the initial call, though they often will. Collectors legally have five days from initial contact to supply it. This legal process, defined in the Fair Debt Collection Practices Act, is called “verification.” Simply asking, “How can I request written verification of this debt,” and getting the paperwork in hand, is good practice. (A sample debt verification letter is here). The process is also called “validation.” Any legitimate collector will not balk at requests for verification or validation.

7. How can I dispute the debt?

Disputing a debit initiates another legal process that requires collectors to produce additional documentation supporting its right to collect, such as paperwork from the original creditor. No one should ever pay a debt bill to a firm that can’t produce paperwork supporting it.

Remember, it’s a good idea to regularly check your credit for any errant or erroneous debit information. You can get your credit reports for free once a year at AnnualCreditReport.com and you can find out how the information they contain affects your credit by checking your credit scores. (You can get your credit scores for free on Credit.com, updated monthly.) If you discover your credit report contains erroneous information, dispute it, but give yourself plenty of time to get the item(s) corrected and the dispute resolved before you apply for a mortgage, car loan, or credit card.