The IRS Whistleblower Office states they will: "process tips received from individuals, who spot tax problems, in their workplace, while conducting day-to-day personal business, or anywhere else they may be encountered."
If you have knowledge of violation of tax law, you must submit the IRS Form 211, Application for Award for Original Information. If you have documents such as books and records to substantiate your claim, you submit them with the IRS Form 211.
Noncompliant taxpayer referrals can be regarding attorneys, CPAs, employers, family members/relatives, as well as corporations and tax exempt organizations.
In 2013 the IRS paid $54 million in awards to 122 whistleblowers.
Of course, the IRS award is considered as ordinary taxable income, and income taxes must be paid on the IRS award?