1099-DA reconciliation
1099-DA is here. Reconcile it before you file.
Brokers now report crypto sales straight to the IRS, and their numbers won't match your client's full history. ChainLedger imports each broker's 1099-DA, matches it line by line against the reconciled ledger, and explains every difference before Form 8949 is signed.
1099-DA reconciliation · Coinbase · 2025
Illustration
| Asset | Sale date | 1099-DA proceeds | Ledger proceeds | Status |
|---|---|---|---|---|
| ETH | 2025-03-14 | 4,812.40 | 4,812.40 | Matched |
| SOL | 2025-05-02 | 1,206.75 | 1,203.91 | Proceeds differ |
| BTC | 2025-08-21 | 18,450.00 | 18,450.00 | No basis from broker |
| ARB | 2025-10-09 | — | 932.18 | Not on 1099-DA |
What changed
Three rule changes your clients' returns now depend on.
Tax year 2025
Gross proceeds reported
Custodial brokers send Form 1099-DA showing gross proceeds for each sale. The IRS sees the proceeds, but basis is often blank.
From 1 Jan 2025
Basis tracked per account
Cost basis has to be tracked wallet by wallet and account by account, not pooled across everything a client holds.
Tax year 2026
Basis reported for covered assets
Brokers start reporting cost basis for assets bought on their platform from 2026. Assets transferred in remain noncovered.
Why it won't match
The 1099-DA shows one broker's view. The return needs the whole picture.
Proceeds on a broker form are only a starting point. These are the differences preparers run into most often.
Transfers in
Coins moved onto an exchange from a wallet arrive with no basis on the broker's side, so the 1099-DA shows proceeds with nothing to offset them.
Self-custody activity
Sales, swaps, and income in a client's own wallets never appear on any 1099-DA, but they still belong on Form 8949.
Several brokers
Each broker reports only its own account. Nobody but the preparer sees the full picture across every exchange.
Fees and netting
Brokers can treat fees and partial fills differently from the client's ledger, which creates small proceeds differences on every line.
Dates and time zones
A sale near midnight can land on a different date or even tax year depending on whether UTC or local time is used.
Staking and DeFi
Rewards, lending interest, and LP activity are income or disposals that a broker's form either covers partly or not at all.
How ChainLedger reconciles
From broker CSV to signed-off schedules.
1. Import the broker's 1099-DA
Upload the broker's CSV. Column headers are detected automatically, so each broker's layout works without manual mapping.
2. Match against the ledger
Each reported sale is matched to a disposal from ChainLedger's per-account Gain/Loss, calculated from the client's full synced history.
3. Flag every difference
Proceeds differences, sales missing from the 1099-DA, and lines with no basis are flagged for review. Numbers are never changed silently.
4. Assign 8949 boxes
Lines go into the right Form 8949 box based on whether the broker reported basis, with adjustment code B applied where a match supports it.
5. Export the schedules
Form 8949, Schedule D, and the crypto income schedule export as PDF, XLS, or CSV, and they tie back to the Gain/Loss report to the cent.
ChainLedger prepares US schedules (Form 8949, Schedule D, crypto income) from FIFO, LIFO, HIFO, or average-cost Gain/Loss. The preparer reviews and confirms every line before it goes on a return.
Get ahead of 1099-DA season.
Bring one client's broker form and wallets. We'll reconcile it with you live and show where the differences come from.