Form 1099-B field reference
Form 1099-B Box 1c: Date sold or disposed
Form 8949 destination
Column (c) — Date sold or disposed of
Reconcile this field with the rest of the transaction before calculating gain or loss. A Form 1099-B label does not override the official basis, holding-period, or adjustment rules.
Before filing
What to check
- Match the transaction to the broker confirmation.
- Keep trade-date and settlement records.
- Use the Form 8949 convention required for your transaction rather than inventing an abbreviation.
How it works
Box 1c mechanics
Brokers generally report Box 1c using the trade date rather than the settlement date, since trade date is the standard convention under the broker basis-reporting regulations. That distinction rarely matters mid-year but can shift a transaction between tax years when a trade executes in the last days of December but doesn't settle until January. Box 1c also covers dispositions that aren't ordinary sales — options expiring worthless, certain corporate reorganizations, and short sales all generate a 1099-B entry with their own timing conventions. Short sales are a particular quirk: the transaction is generally reported for the year the short position is closed (bought to cover), not the year it was opened, so a short position carried across year-end appears on the following year's form even though the trade began earlier.
Worked example
A taxpayer opens a short sale in December 2025 and closes it (buys to cover) in January 2026. Even though the short position was entered in 2025, the 1099-B and Form 8949 date-sold generally fall in 2026, because a short sale is reported based on when the position closes. The gain or loss belongs on the 2026 return, not 2025.
Box 1c FAQs
Is Box 1c always the settlement date?
No. Brokers generally report the trade date, not the settlement date. Confirm which convention applies if a transaction falls right at year-end.
Why doesn't my short sale show up on the 1099-B for the year I opened it?
Short sales are generally reported for the year the position closes, not the year it was opened. A short sale spanning year-end shows up on the following year's form.