What additional information is needed to report a transaction from a Form 1099-B showing net proceeds?

To accurately report a transaction detailed on Form 1099-B, it is essential to know both the date(s) the asset was acquired and the asset basis on the sale date. Understanding the acquisition date provides context for determining the holding period of the asset, which is important for tax implications, such as differentiating between short-term and long-term capital gains. Additionally, the asset basis—or the amount paid for the asset—plays a critical role in calculating the gain or loss when the asset is sold.

If only the basis or acquisition date were known independently, it would not provide a complete picture for reporting. For example, without the acquisition date, determining the holding period would be impossible, affecting how the gain is taxed. Similarly, knowing just the acquisition date without the basis would not allow for an accurate gain or loss calculation.

Therefore, both pieces of information work together to support the correct reporting of the transaction on a tax return, making the selection that includes both the acquisition dates and the asset basis the most comprehensive and necessary for accurate tax reporting.