As Uncle Sam cracks down on overdue taxes, scammers are moving to cash in. Getty images By Rivan V. Stinson, Staff Writer From Kiplinger's Personal Finance, August 2017 An IRS program to use private debt collectors to recoup back taxes on some accounts has attracted scammers looking to cash in. The IRS began turning over some 140,000 seriously delinquent accounts to collectors in April. This summer, consumers should be especially wary of callers claiming to represent the IRS.See Also: 8 Worst Things to Keep in Your Wallet Phone scams are among the most common forms of tax fraud, taking the number-two spot (behind e-mail and website scams that seek to steal personal data) on the IRS’s “Dirty Dozen” list for 2017. The IRS’s first contact with taxpayers is never a phone call, and the same goes for collectors employed by the IRS. The agency and the assigned debt collector must each send a letter informing you of an account transfer before the debt collector may contact you by phone. Currently, the IRS has contracts with only four collection agencies: CBE Group, ConServe, Performant and Pioneer Credit Recovery. If you haven’t received a letter, a call is a red flag. Ask which company the caller represents and get a name and contact number so you can follow up with the IRS before divulging any information. Hang up if you’re badgered about paying on the spot. Payments are not made to the debt collector but to the U.S. Treasury, by check or electronically on the IRS website. Quiz: Is Your Identity at Risk?