There's a U.S. Tax Court case that says this: if a taxpayer has evidence that contradicts a notice of deficiency from the IRS, the IRS can’t just rely on a Form 1099 or W2 as proof that the taxpayer underpaid.
That doesn’t mean, as people have apparently, and erroneously, claimed, that Forms 1099 and W2 can’t be used as evidence of income in tax court. It just means that the IRS can’t rely on a 1099 or W2 alone where the taxpayer presents contradictory evidence.
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