What makes a tax-fraud report credible enough to be useful?

Credibility comes from specific facts, not dramatic wording. A useful report should identify the person or business, the tax years, the type of violation, approximate amounts if known, and documents or observations supporting the allegation.

For example, "a vendor omitted about $48,000 of cash receipts from 2025 invoices based on numbered receipt books and bank deposits" is more useful than "everyone in that shop cheats." The first statement gives who, what, when, how, and a record trail. The second is only a conclusion.

For EA exam purposes, remember that Form 3949-A can be used for alleged tax-law violations, but the IRS still needs specific, credible information. If the issue is instead preparer misconduct or an affected return or refund, choose the preparer complaint lane.