What records do I need to keep for the IRS as a self-employed person?

Keep enough to prove both your income and every deduction. That means receipts and invoices, bank and credit-card statements for business accounts, a mileage log, records of asset purchases (for depreciation), proof of estimated tax payments, and 1099s you receive. For each deductible expense, the amount, date, and business purpose should be documented — a receipt plus a quick note. The general rule is to keep records for at least three years after filing (the normal audit window), but six years if you under-reported income substantially, and indefinitely for anything tied to property you still own or for returns you never filed. Digital copies are fine and far easier to manage. The single biggest habit that makes this painless is a dedicated business bank account and card, so your statements already form most of the audit trail.