IRS Form 1065 is a tax form used by partnerships to report their income, deductions, gains, and losses to the Internal Revenue Service (IRS). This form helps the IRS understand the financial activities of the partnership, ensuring that all income is properly reported and taxed. Each partner in the partnership receives a Schedule K-1 from Form 1065, which details their share of the partnership's income, deductions, and credits. Partners then use this information to report their individual tax obligations on their personal tax returns.