A common mistake freelancers make when filing taxes is misunderstanding their quarterly estimated payments, often resulting in hefty IRS penalties. Independent contractors must proactively pay taxes quarterly rather than annually—overlooking this can lead to unexpected debts. Another frequent misstep involves inaccurately handling 1099 forms by neglecting to report all income listed, triggering audits. To avoid this, meticulously track income from all sources and match it against your 1099s. Additionally, many overlook valuable self-employment deductions such as home-office costs, software subscriptions, and health insurance premiums, missing opportunities to significantly reduce taxable income.