Form 1099-B (Proceeds From Broker and Barter Exchange Transactions) is filed by brokers and barter exchanges to report each customer’s sales of stocks, bonds, commodities, and other securities — and their bartering income. For covered securities, brokers also report cost basis and whether the gain is short- or long-term; for noncovered securities they generally report proceeds only. The recipient copy is due February 15. Crypto sales now belong on the new Form 1099-DA instead.
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Who Files a 1099-B
The 1099-B is a broker’s form. If you effect sales of securities for customers — a brokerage, a mutual fund company, a barter exchange — you report those sales, one line of detail per transaction or per aggregated group the rules allow.
A separate form (or a substitute statement, which is how most brokers actually deliver it) goes to each customer who sold a security through you during the year. Barter exchanges use the same form to report the value of goods and services their members traded. The customer uses it to fill out Form 8949 and Schedule D.
One thing has shifted recently. Digital-asset sales that brokers used to squeeze onto the 1099-B now belong on the purpose-built 1099-DA. If you run a crypto platform, that’s your form now — the 1099-B stays for traditional securities.
Covered vs. Noncovered Securities: The Basis Divide
The single most important distinction on the form is whether a security is covered or noncovered, because that decides whether you have to report cost basis. Covered securities are ones acquired after the basis-reporting rules took effect for their asset class — stocks from 2011 on, mutual fund and DRIP shares from 2012, most debt and options from 2014. For those, you report the customer’s basis and holding period to the IRS.
Noncovered securities — typically older lots the customer held before those dates, or transferred in without basis information — get proceeds reported, but basis is optional and usually left to the taxpayer. The customer still has to supply basis on their own return; you just aren’t certifying it.
Box 5 flags a noncovered security and Box 12 flags that basis was reported to the IRS. If you check Box 12 on a lot whose basis you don’t actually know, you’re certifying a number to the IRS that may be wrong — and the customer inherits the mismatch. When basis is uncertain, mark it noncovered rather than guessing.
Form 1099-B, Box by Box
Most of the action is in Box 1, which breaks into lettered sub-boxes describing a single sale. The rest handle contracts, withholding, and the covered/noncovered flags.
| Box | What goes in it |
|---|---|
| Box 1a — Description | The property sold (for example, 100 sh. XYZ Co.). |
| Box 1b — Date acquired | When the customer acquired the lot. |
| Box 1c — Date sold or disposed | When the sale settled. |
| Box 1d — Proceeds | Gross or net proceeds from the sale. |
| Box 1e — Cost or other basis | The customer's basis — required for covered securities. |
| Box 1f — Accrued market discount | Market discount treated as ordinary income. |
| Box 1g — Wash sale loss disallowed | Loss disallowed under the wash-sale rule. |
| Box 2 — Short/long-term | Holding period, and whether the gain is ordinary. |
| Box 3 — Proceeds from | Check if from a collectible or a QOF (Qualified Opportunity Fund). |
| Box 4 — Federal income tax withheld | Backup withholding, if any. |
| Box 5 — Noncovered security | Check if the security is noncovered. |
| Box 6 — Reported to IRS | Whether Box 1d is gross or net proceeds. |
| Box 7 — Loss not allowed | Check if a loss is disallowed based on the Box 1d amount. |
| Boxes 8–11 — Section 1256 contracts | Realized and unrealized profit/loss on regulated futures and similar contracts. |
| Box 12 — Basis reported to IRS | Check if basis was reported to the IRS. |
| Box 13 — Bartering | Income from a barter exchange. |
| Boxes 14–16 — State information | State tax withheld, state number, and state income. |
Wash Sales: Box 1g in Practice
A wash sale happens when a customer sells a security at a loss and buys a substantially identical one within 30 days before or after the sale. The loss is disallowed for now and the amount rolls into the basis of the replacement shares. On the 1099-B, that disallowed amount goes in Box 1g.
Here’s the catch brokers have to respect: your wash-sale reporting is limited to identical securities in the same account. If the customer triggered a wash sale across two different brokers, or between an IRA and a taxable account, you won’t see it and won’t report it — but the taxpayer still has to. So Box 1g is a floor, not a complete picture, and the recipient copy should make that clear.
Where 1099-DA Fits In
For years, crypto brokers had no form built for digital assets, so they improvised with the 1099-B. That era is ending.
The new Form 1099-DA is purpose-built for digital-asset proceeds, with dedicated fields for units, acquisition and sale dates, proceeds, and eventually cost basis. Custodial digital-asset brokers report there now, not on the 1099-B. If you handle both traditional securities and crypto, you’ll file both forms — 1099-B for the stocks and bonds, 1099-DA for the digital assets.
The good news is that the mechanics are familiar. Covered-vs-noncovered logic, proceeds-then-basis phase-in, the same February-ish recipient timing — if you already file 1099-Bs at volume, the DA won’t feel foreign. It’s the same reporting instinct on a form that finally fits the asset.
Deadlines and Filing Through IRIS
The 1099-B recipient copy is due February 15 — later than the January 31 that governs the NEC — because brokers need the extra time to finalize basis and holding-period data. The IRS copy follows the usual information-return schedule: February 28 on paper, March 31 if you e-file. And brokers file at volume, so e-filing through IRIS is the reality, not the exception.
IRIS accepts the 1099-B natively, so all those lettered Box 1 sub-fields map to real XML elements instead of getting flattened. With e1099f you upload the file you already produce and it’s converted to validated IRIS XML — no new TCC, no 45-day wait.
Covered basis handled
Covered vs. noncovered logic and Box 12 flags map to the right IRIS fields.
Pre-validated
Every record is checked against the IRS business rules before we submit.
Volume-ready
Bulk filing and recipient statements for brokers with high transaction counts.
A Receipt ID from the IRS — not a rejection — for every 1099-B you send.
Filing broker proceeds at volume?
Upload your existing file — we convert it to validated IRIS XML and file it for you.
Frequently Asked Questions
Who has to file a 1099-B?
What is the difference between covered and noncovered securities?
When is Form 1099-B due?
How are wash sales reported on a 1099-B?
Does 1099-B still cover cryptocurrency?
Can I file 1099-B through IRIS?
Not tax advice. This guide is general information for filers and may not reflect the latest IRS rules; thresholds and amounts change. Confirm current-year requirements with the IRS or a tax professional before you file.