How do I estimate my first year of quarterly taxes when I have no prior return?

With no prior-year return to lean on, base your estimates on a realistic projection of net profit, then apply both self-employment tax (about 15.3% before the half deduction) and your expected income tax bracket. A common shortcut is setting aside 25% to 30% of net profit and paying it across the four IRS deadlines using Form 1040-ES. Because the safe-harbor rule that shields you from penalties depends on last year's tax, first-year filers have no cushion, so aim to pay at least 90% of what you will actually owe. Recalculate each quarter as real numbers come in. The self-employed hub at wealthserene.com/tools/self-employed-hub can help you size the set-aside.