Approximately $1.3 trillion in income goes underreported annually on U.S. federal tax returns, contributing to a gross tax gap of over $600 billion. Underreporting, primarily from small business income and informal, cash-based, or side-gig work, accounts for nearly 80% of this total tax gap.
We estimate $1.33 trillion of income goes underreported on federal income tax returns.
Underreported income happens when the amount of income you list on your tax return is less than what the IRS has on file from employers, financial institutions, gig platforms, or other third-party sources.
You have to file an income tax return if your net earnings from self-employment were $400 or more. If your net earnings from self-employment were less than $400, you still have to file an income tax return if you meet any other filing requirement listed in the Form 1040 and 1040-SR instructions PDF.
Who must file. Generally, any person in a trade or business who receives more than $10,000 in cash in a single transaction or in related transactions must file a Form 8300. By law, a "person" is an individual, company, corporation, partnership, association, trust or estate.
No, the IRS doesn't catch every instance of unreported income, but their advanced data-matching systems catch most discrepancies involving third-party reporting (like W-2s, 1099s for freelance/interest/dividends) through automated checks, leading to CP2000 notices and potential penalties if missed; however, cash income, crypto, or lifestyle mismatches can also trigger scrutiny, though it's less certain than reported income, and high-income non-filers are a current focus.
Unemployment compensation generally is taxable. Inheritances, gifts, cash rebates, alimony payments (for divorce decrees finalized after 2018), child support payments, most healthcare benefits, welfare payments, and money that is reimbursed from qualifying adoptions are deemed nontaxable by the IRS.
If you don't include taxable income on your return, it can lead to penalties and interest. The IRS may charge penalties and interest beginning from the date they think you owe the tax.
The voluntary compliance rate (a technical measurement of taxes being paid both on time and voluntarily) in the US is generally around 81 to 84%. This is one of the highest rates in the world. By contrast, Germany's voluntary compliance rate is 68%, and Italy's is 62%.
If your panicking about going to prison, those numbers should provide some perspective. The overwhelming majority of people with unreported income never face criminal charges. They face civil penalties, audits, payment plans – but not prison.
Not reporting all of your income is an easy-to-avoid red flag that can lead to an audit. Taking excessive business tax deductions and mixing business and personal expenses can lead to an audit. The IRS mostly audits tax returns of those earning more than $200,000 and corporations with more than $10 million in assets.
If you haven't lodged a tax return for a few years or you have one outstanding or overdue – no matter your reason – get up to date for peace of mind. If you don't lodge, the ATO can apply a number of sanctions and penalties to force you to lodge or penalise you for lodging late.
What happens during an audit? Internal audit conducts assurance audits through a five-phase process which includes selection, planning, conducting fieldwork, reporting results, and following up on corrective action plans.
Ten Red Flags that Could Trigger an IRS Audit
Depositing $2,000 in cash isn't inherently suspicious and is well below the $10,000 reporting threshold for banks, but it can raise flags if it's part of a pattern (structuring), inconsistent with your normal income, or involves other red flags like frequent large cash deposits from others, leading to a potential Suspicious Activity Report (SAR). To avoid issues, have clear records for the cash's source, like invoices or sales receipts, especially if you deal in cash often.
Yes, you can likely give your daughter $50,000 tax-free by using your annual gift exclusion and lifetime exemption, but you'll need to file Form 709 with the IRS to report the gift exceeding the annual limit ($19,000 in 2024/2025). The $50,000 gift reduces your large lifetime exemption (over $13 million in 2024/2025), meaning you won't pay tax on it unless your total lifetime gifts exceed that huge amount; your daughter never pays gift tax on the money.
How far back can the IRS go to audit my return? Generally, the IRS can include returns filed within the last three years in an audit. If we identify a substantial error, we may add additional years. We usually don't go back more than the last six years.