§ Form 1040

2025 Form 1040, Line 26

Estimated Tax Payments: Line 26 and the Quarterly Rhythm

By Paul D. Diaz, EA, MBA · Updated

Line 26 totals your 2025 estimated payments — the four 1040-ES installments plus any prior-year overpayment you elected to apply forward. It is the pay-as-you-go ledger for income that arrives without withholding.

The 1040-ES mechanics

Each installment is a payment of 2025 tax made during 2025: by paper 1040-ES voucher, Direct Pay, EFTPS, or card. Add every installment you actually paid, plus any 2024 overpayment you checked the box to apply forward — that election is irrevocable, and it counts here, not on the prior-year return.

The quarterly rhythm

Four due dates pace the year: mid-April, mid-June, mid-September, and mid-January after year-end. Miss a beat and the IRS notices the timing, not just the total — a big January payment does not retroactively cover April. Withholding, by contrast, is treated as paid evenly all year no matter when it was withheld.

Safe harbors live next door

Paying something is not the same as paying enough: the underpayment penalty turns on whether your withholding and estimates hit a safe harbor, on time, installment by installment. The full safe-harbor detail lives on the amount-owed page — read it before you size your vouchers. For the payments playbook end to end, see chapter 4 of the Guide.

From the practice: How tax, credits, and payments fit together — chapter 4 →

Questions, answered

What goes on Line 26?
Every 2025 estimated payment you made — all four 1040-ES installments plus any 2024 overpayment you elected to apply to 2025.
When are estimated payments due?
Four installments across the year: mid-April, mid-June, mid-September, and mid-January after year-end, paid by 1040-ES voucher or electronically.
How do I avoid the underpayment penalty?
Hit a safe harbor — pay enough, early enough, through withholding and estimates. The full safe-harbor detail lives on the amount-owed page.

Keep reading: Amount Owed · Refund or Owed · Schedule 3

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