The extended filing deadline for individual federal income tax returns for the 2025 tax year is October 15. The IRS clarifies that this date applies to taxpayers who previously requested an extension and emphasizes that extensions grant additional time to file, not to pay any taxes owed. Crypto traders must verify their reported information before submitting returns, as Form 1099-DA provided by brokers for digital asset transactions may not include cost basis data. Taxpayers remain responsible for independently calculating gains or losses and accurately reporting them to ensure compliance with federal requirements.