For years, you've been told the IRS will never call you, but that is changing.

The IRS is now working with third party debt collectors, who may be giving you a call on behalf of the IRS.

So how can you tell whether the person calling you is legitimate or a scammer? Ask the following questions:

1. Is the person calling from one these four private-collection firms?

- CBE Group of Cedar Falls, IA

- Conserve of Fairport, NY

- Performant of Livermore, CA

- Pioneer of Horseheads, NY

The IRS is only working with these four private-collection agencies. If one of them isn't on the other line, hang up.

2. Did you get a letter first?

The IRS will always send you a letter notifying you that one of the above firms will be contacting you. Then, that firm will send you a second letter, before finally contacting you by phone. If you have someone calling you before you get a letter or are notified, it's a scam.

3. Are they pushy?

The IRS never uses strong-arm tactics, and neither will the agencies they work with. Therefore, if they are being pushy or threatening you, hang up.

The IRS will also, never ask you to pay a debt by pre-paid debit or iTunes cards.