Premium cash is not the estimated-tax number
A brokerage account credits premium when a call is written, but the federal tax result generally remains open. If the call expires, the writer recognizes the premium as short-term gain. If it is bought back, the close cost changes the result. If assigned, the premium generally becomes part of the stock sale proceeds and the selected lot's basis and holding period drive the gain.
Estimated tax therefore starts with a closed-transaction ledger, not a list of deposits. Net capital losses, other gains, wages, interest, dividends, retirement income, deductions, credits, and withholding all affect the household calculation. Setting aside a flat percentage of every premium can be a cash-management habit, but it is not a substitute for Form 1040-ES.
The 2026 general payment test
A safe harbor addresses the federal underpayment penalty, not the final amount of tax. A writer can satisfy the prior-year target and still owe a large balance when filing if 2026 gains are much higher. Reserve cash for both the installments and the expected return balance.
- First test: expected 2026 tax due after withholding and refundable credits is at least US$1,000.
- Second test: withholding and refundable credits are less than the smaller of 90% of 2026 tax or 100% of 2025 tax.
- Higher-income adjustment: use 110% instead of 100% when 2025 AGI exceeded US$150,000, or US$75,000 for married filing separately.
- The 2025 return must cover all 12 months for the prior-year safe harbor.
- Special rules apply to farmers, fishers, nonresident aliens, and some other taxpayers.
Worked safe-harbor calculation
If the filer's 2025 AGI had exceeded the higher-income threshold, the prior-year target would be US$26,400: US$24,000 × 110%. The smaller target would then be US$26,400 rather than US$27,900, and expected withholding would leave US$11,400 to cover. Always take the figures from the filed prior return and current forecast.
| Step | Calculation | Amount |
|---|---|---|
| Expected 2026 total tax | Forecast | US$31,000 |
| 90% current-year target | US$31,000 × 90% | US$27,900 |
| 100% prior-year target | 2025 total tax | US$24,000 |
| Required annual payment | Smaller target | US$24,000 |
| Expected withholding | Payroll and other withholding | US$15,000 |
| Estimated payments needed | US$24,000 − US$15,000 | US$9,000 |
| Four equal installments | US$9,000 ÷ 4 | US$2,250 |
2026 federal installment calendar
These are not four equal three-month periods, which is one reason a calendar reminder and cumulative worksheet help. Fiscal-year filers use different dates. Payment extensions and disaster relief can also change deadlines, so confirm the current IRS notice for the taxpayer's location and facts.
| Payment | Due date | Planning action |
|---|---|---|
| First | April 15, 2026 | Reconcile early expirations, closes, and assignment |
| Second | June 15, 2026 | Update cumulative income and withholding |
| Third | September 15, 2026 | Add summer option and stock results |
| Fourth | January 15, 2027 | Finalize 2026 estimate before return filing |
Use annualization for a late assignment spike
Suppose option income is modest through September and a December assignment realizes a six-figure stock gain. Paying four equal installments as though the gain existed in January can overstate earlier-period requirements. Publication 505's annualized-income installment method calculates the required amount from income accumulated through each period, and Form 2210 Schedule AI documents that timing with the return.
Annualization is more work: every period needs cumulative income, deductions, capital-gain calculations, credits, and payments. But it can reduce or eliminate a penalty attributed to quarters before the gain occurred. Save assignment statements and lot records that establish the actual recognition date.
A repeatable option-writer tax routine
The linked covered-call tax, Schedule D, income-tax, and assignment calculators can structure the inputs. The official Form 1040-ES and Publication 505 determine the federal payment. When gains are large, lots are complex, or annualization is needed, a tax professional can review the calculation before the next deadline rather than after a penalty notice.
- Tag every written call as open, expired, closed, or exercised; only settled outcomes enter the realized ledger.
- For assignment, record strike proceeds, premium, selected stock basis, and holding period together.
- Recalculate after large rolls, assignments, capital-loss harvesting, withholding changes, or household income changes.
- Pay through an official IRS channel and retain the tax year, amount, date, and confirmation number.
- Run a separate state worksheet and reserve for any filing balance beyond the penalty safe harbor.
Related Internal Guides
- How Are Covered Calls Taxed IRS 2026
- Covered Call Tax Implications Guide
- Covered Call Assignment What Happens 2026
- Covered Call Wash Sale Rule: How Options Trigger It 2026
Calculators Mentioned
- Covered Call Tax Calculator
- Income Tax Calculator
- Capital Gains Tax Calculator
- Covered Call Income Calculator
- Covered Call Schedule D Calculator
- Options Assignment Calculator
Official Sources
- IRS Publication 505 (2026) — Tax Withholding and Estimated Tax: Current 2026 IRS guidance on pay-as-you-go tax, estimated payments, capital gains, safe-harbor calculations, and the annualized-income method.
- IRS Form 1040-ES (2026) — Estimated Tax for Individuals: The official 2026 worksheet, payment vouchers, general payment test, higher-income safe-harbor rule, and installment dates.
- IRS Form 2210 — Underpayment of Estimated Tax: IRS form for determining an underpayment penalty and using Schedule AI when income is uneven during the year.
- IRS Publication 550 — Investment Income and Expenses: IRS guidance on written options, exercise and assignment, investment interest, stock basis identification, holding periods, and qualified covered calls.
- IRS Instructions for Form 8949: IRS instructions for reporting capital-asset dispositions and correcting option premiums or basis information not reflected on Form 1099-B.