A large crypto gain. Review your estimated payments.

Start with the gain and the tax already paid

A large crypto gain is a reason to review your payments during the year. Federal tax is paid through withholding, estimated payments or both; underpayment can lead to a penalty even when the eventual return shows a refund. A filing-date balance alone does not explain whether earlier payments were sufficient.

This guide focuses on calendar-year individual investors reviewing 2026. Start with a dated sale record, supported acquisition information, your prior return and the payments already made. A business, nonresident situation or special relief provision can need a different review.

Establish the gain before estimating the tax

Sale proceeds are not automatically your taxable gain. For a digital asset held as an investment, the calculation uses the amount realized and adjusted basis. Keep the purchase and sale evidence together, including records from an earlier platform when an asset was transferred before it was sold.

California does not offer a separate lower capital-gains rate. The state calculation must therefore be considered alongside the federal calculation. Neither a fixed percentage of sale proceeds nor a rate copied from a general crypto article answers your payment question.

• Sale or exchange date, asset, quantity and proceeds
• Acquisition dates, purchase records and relevant costs
• The accounts or wallets connecting acquisition and disposal
• Other income, losses or unresolved entries in the same year

Compare the federal and California calendars

The standard 2026 calendar below shows installment dates and shares of the required annual payment, not percentages of your crypto profit. The federal regular method generally uses equal installments; California uses a different distribution. Withholding, prior payments and the method used affect the amount still due.

The September state share of 0% does not remove a prior shortfall. Uneven income can require a different calculation. Use the calendar as a starting point and check any applicable disaster relief or other exceptions before relying on a date.

Check which annual-payment rule applies

For federal purposes, the general test includes whether you expect at least $1,000 due after withholding and refundable credits. The annual-payment benchmark is usually the smaller of 90% of current-year tax or 100% of prior-year tax, with a full-year prior return. For higher prior-year AGI, 110% replaces 100%; the threshold is over $150,000, or $75,000 for married filing separately.

California generally has a $500 threshold after withholding and credits ($250 for married/RDP filing separately). Its prior-year comparison also changes for higher income. Crucially, with 2026 California AGI of at least $1 million ($500,000 for separate filing), use current-year tax rather than the prior-year benchmark. Review the worksheet and exceptions for your situation.

A prior-year benchmark is often called a safe harbor. It concerns the required prepayments, not a cap on the final tax bill. Bring the prior return and current projection to the same review; a payment total without its dates is incomplete.

Review when the gain occurred

A gain concentrated late in the year may call for the annualized income installment method. Federal and California guidance allow a review based on income during the relevant periods. This requires period-by-period information; it does not mean choosing a convenient payment date.

For the federal method, Publication 505 explains Form 2210 and Schedule AI. California uses its own annualization review. Keep earlier income, deductions and payment evidence available rather than submitting only the large sale.

Include payroll withholding and payment confirmations

If you receive wages, additional withholding may be part of the plan. The federal adjustment uses Form W-4; California withholding uses Form DE 4. Review what can actually be withheld through the remaining payroll periods.

Keep federal and state payment records separate. For each payment, retain the date, tax year, amount and confirmation. Compare those records with account information where available. An amount saved in a bank account is a reserve; the review also needs evidence of tax actually paid.

Gather a compact payment-review packet

Prepare a one-page timeline before sending a large folder. Identify the sale date, whether acquisition history is complete, what was paid and which question needs an answer. Keep original exports and confirmations unchanged; label working calculations separately.

Include other platforms even if the large sale took place on only one exchange. Note anything still uncertain, such as a missing purchase, unexplained transfer or unconfirmed payment. Naming the gap helps define the review.

• Prior federal and California returns, including relevant schedules
• Current pay statements showing year-to-date withholding
• A dated list of federal and state estimated payments
• Sale records, acquisition evidence and the crypto report version used
• A summary of other income and changes expected before year-end
• Residency changes, any notice, and a list of unresolved questions

Discuss the payment question with Nancy

An initial message can say: the tax year, when the gain occurred, whether you live in California, and whether withholding or estimated payments have already been made. Mention the records available and any deadline you are reviewing.

Nancy will discuss whether the question fits a consultation and confirm the work, documents, fee and timing. A consultation, transaction reconstruction and return preparation have separate scopes; contacting Nancy does not arrange a tax payment or filing. Agree how to share detailed documents after that discussion.

Common questions