Form 1099-DA Explained, Box by Box
What each box means, why basis is so often blank, and how to carry the form onto Form 8949 so the IRS matching system has nothing to flag.
TL;DR
Form 1099-DA is the crypto version of Form 1099-B. Forms for 2025 sales show gross proceeds only. From 2026 sales onward, brokers also report basis — but only for covered assets: bought after 2025 in that broker’s custody and never moved. Everything else can arrive with basis blank. Report every line on Form 8949 in boxes G–L, with basis you can document, or expect the IRS to see proceeds with nothing against them.
What Form 1099-DA is
Form 1099-DA, Digital Asset Proceeds From Broker Transactions, is the information return a crypto broker files with the IRS — and sends to you — for sales, exchanges, and other dispositions of digital assets. It sits alongside the Form 1099-B you get from a stock brokerage, and the IRS uses it the same way: to match what the broker reported against what is on your return.
It arrives in two stages. For 2025 sales, brokers reported gross proceeds only; the basis boxes could be left blank for everyone. For 2026 sales — on forms furnished in early 2027 — brokers must also report cost basis for covered assets. That second stage is where most investors will see, for the first time, how incomplete their broker’s picture of them is.
Covered vs. noncovered: the question that matters
Under the 2026 instructions, a digital asset is a covered security if it was acquired after 2025 in an account where the broker provided custodial services, and held there until it was sold. Only covered securities require basis reporting.
That leaves a large category of noncovered assets, including:
- anything you bought before 1 January 2026, even if it never left the exchange;
- anything transferred in from a self-custody wallet or another exchange, whenever it was bought;
- assets held outside a broker’s custody, such as DeFi positions.
For noncovered sales, the broker may check box 9 and leave the basis boxes blank. Basis reporting on those is optional for the broker — but the basis still has to be right on your return, and only your records can support it.
The boxes that matter, one by one
The form has more boxes than these, but these are the ones that decide whether your return ties out.
| Box | What it shows | Why it matters |
|---|---|---|
| 1a–1c | Asset code, name, and units sold | Identifies which asset, and how many units, each line covers. |
| 1d / 1e | Date acquired / date sold | Sets short- versus long-term. 1d may be blank on noncovered sales. |
| 1f | Proceeds | The number the IRS matches. Every dollar here must appear on Form 8949. |
| 1g | Cost or other basis | Required for covered sales from 2026. Often blank for noncovered assets. |
| 1i | Wash sale loss disallowed | New for 2026. Applies to tokenized securities treated as stock or securities — not to ordinary spot crypto. |
| 2 | Basis reported to IRS | Checked when the IRS has the basis figure. Decides box G/J versus H/K on Form 8949. |
| 8 | Broker relied on customer-provided acquisition information | The broker used lot information you supplied. If it was wrong, so is the form. |
| 9 | Noncovered security | Tells the IRS basis may be missing. Your records carry the burden. |
| 12a / 12b | Units transferred in / transfer-in date | Flags assets moved into the account — the most common source of missing or wrong basis. |
Two things this table cannot show you: which of your own wallet-to-exchange transfers were treated as purchases, and whether the broker’s default lot method matches what you intended to sell. Both need checking against your records.
Carrying it onto Form 8949
Form 8949 now has separate boxes for digital assets. The instructions are explicit that boxes C and F are not used for them.
| Situation | Short-term (Part I) | Long-term (Part II) |
|---|---|---|
| 1099-DA shows basis reported to the IRS | Box G | Box J |
| 1099-DA without basis, or basis not reported to the IRS | Box H | Box K |
| No 1099-DA received for the transaction | Box I | Box L |
When the broker’s basis is wrong — common with transferred-in coins — report the proceeds and basis exactly as shown on the form, enter code B in column (f), and put the correction in column (g). The return then ties to the 1099-DA line by line, and the adjustment is visible and documented rather than silently different.
Basis itself is tracked wallet by wallet. Rev. Proc. 2024-28 provided a safe harbor for allocating unused basis across wallets and accounts as of 1 January 2025; universal pooling across all wallets no longer works going forward. If you never documented that allocation, it is worth doing now, before it becomes an argument.
How mismatches become CP2000 notices
The IRS Automated Underreporter program compares information returns with filed returns. If a 1099-DA shows $80,000 of proceeds and the return shows nothing — or shows the sales in a way that does not tie — the system can propose tax as though the entire $80,000 were gain, plus an accuracy-related penalty and interest. That proposal arrives as a CP2000.
Because the 2025 forms carried no basis at all, and basis reporting starts only for assets acquired after 2025, the years with the most mismatch risk are the ones already in the system. Notices typically follow the filing season by a year or more.
What to do before the 2027 forms arrive
- Sort every holding into covered or noncovered, and flag every transfer between your own accounts.
- Tie your 2025 1099-DAs to your 2025 Form 8949. If you are on extension, the deadline is 15 October 2026. If you have already filed and something is missing, consider amending before a notice arrives.
- Download complete transaction histories from every exchange, and record every wallet address by chain.
- Confirm your name and taxpayer ID on file with each broker. Under Notice 2025-33, backup withholding on digital-asset sales is deferred until 1 January 2027.
- Decide your lot method deliberately, and communicate specific identification to the broker where you use it.
All of it is on one page in the free 1099-DA Readiness Checklist. To see what a blank basis box could cost you, try the 1099-DA Exposure Calculator.
General information current as of September 2026, based on the 2026 Instructions for Form 1099-DA and the Instructions for Form 8949. It is not tax advice for any particular taxpayer; the right answer depends on your facts. Rules for digital assets are changing quickly — confirm the rules for your filing year before acting.