Form 1099-B field reference
Form 1099-B Box 1d: Proceeds
Form 8949 destination
Column (d) — Proceeds
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
- Confirm whether commissions or transfer taxes were reflected in proceeds or basis.
- Reconcile the amount to the broker detail statement.
- Use Form 8949 adjustment columns when the IRS instructions require a reconciliation.
How it works
Box 1d mechanics
Under the broker basis-reporting regulations, Box 1d is generally reported net of selling commissions and transfer taxes — the broker subtracts them before the figure ever reaches the form, rather than leaving that adjustment to the taxpayer. That matters because subtracting a commission a second time on Form 8949 understates gain (or overstates a loss). Bond sales carry an additional wrinkle: accrued interest that the buyer pays the seller as part of the purchase price is generally excluded from Box 1d proceeds and reported separately as interest income, not capital gain. Option transactions have their own proceeds conventions that don't always look like a straightforward stock sale, so premium received or paid on options can appear in a different place on the statement than the underlying security's Box 1d entry.
Worked example
A sale generates $10,000 in gross proceeds with a $25 broker commission. Box 1d typically already reflects the commission being netted out under the broker-reporting convention, showing $9,975 rather than $10,000. Subtracting the $25 commission again on Form 8949 would double-count it and understate the reported gain.
Box 1d FAQs
Should I subtract my own commission if Box 1d already looks net of fees?
Only if you can confirm from the broker's detail statement that it wasn't already netted. Double-subtracting a commission that's already reflected in Box 1d understates gain.
Are option premiums included in Box 1d the same way as a stock sale?
Not always. Option-related proceeds have their own reporting conventions and can appear differently than a straight stock sale, so review the broker's options detail before matching amounts to Form 8949.