Form 1099-B

What Is Form 1099-B?

Form 1099-B is an information return that brokerage firms send each year to their clients and to the Internal Revenue Service (IRS). It reports the results of sales and certain other dispositions of securities made through an account during the tax year. It belongs to the broader Form 1099 family, which covers many kinds of payments reported to recipients. For investors, it is the main annual summary of trading activity needed to prepare a US federal income tax return.

How It Works

Each entry typically shows a description of the security, the dates acquired and sold, the sales proceeds, and the cost basis. For a covered security, the broker reports the cost basis directly. For other holdings, the form may show proceeds only, leaving the investor to supply the basis from personal records. The form also indicates whether each gain or loss is short-term or long-term, based on how long the position was held. It may also show adjustments for a wash sale when the broker can identify one.

Using the Form

Investors generally transfer these figures to Form 8949 and then to Schedule D of their federal return, where capital gain and loss totals are calculated. Brokers sometimes issue a corrected form later, for example when basis information changes or a late adjustment is made, so investors often check whether an updated version exists before filing. Comparing the form with trade confirmations and account statements is a common way to catch missing or mismatched data.

Why It Matters

The IRS receives a copy of the form, so the figures on a return are generally compared against what brokers report. Accurate cost basis helps avoid reporting more gain than was actually earned, and an incorrect or missing basis can lead to a larger tax bill or correspondence from the IRS. The form covers only the accounts of the broker that issued it. Gains from assets held at other firms, or in holdings that a broker does not report, are not included and must be tracked separately.