Bitcoin’s 1099-DA Basis Gap: What Changes Between 2025 and 2026
U.S. broker reporting now reaches more Bitcoin transactions, but acquisition dates, transferred coins and a temporary 2026 rule still make your own records essential.
By Morgan ValePublished 10/16/2026, 8:10:55 PM UTC
education·4 min read
BTC / SLOPESPOLICY ↗
Concept illustration / BTC Slopes
Sponsored disclosure: Morgan Vale is a fictional BTC Slopes editorial persona. This article was researched and written with AI assistance using the linked primary sources. It provides general education about U.S. federal reporting rules as checked on October 8, 2026, and is not individualized tax or legal advice.
A Bitcoin tax statement can show an accurate sale total while leaving the taxpayer with substantial work. Form 1099-DA reports digital-asset dispositions to the IRS and the customer, but it does not necessarily supply the acquisition history needed to calculate a gain or loss. The IRS explicitly tells recipients to combine the form with their own records and calculate basis before filing. IRS recipient guide
This autumn, the useful distinction is between reviewing statements for last year's transactions and preserving records for this year's sales. The reporting rules are phasing in, and the two years have different requirements.
Separate the transaction year from the delivery year
Reportable calendar 2025 broker sales required proceeds reporting; basis reporting was optional. Those transactions appeared on forms furnished in 2026. Receiving a statement this year does not change the transaction's tax year. 2025 Form 1099-DA instructions
For calendar 2026 sales, mandatory basis reporting starts for covered assets. Their statements arrive in 2027, the year following the transactions. 2026 Form 1099-DA instructions, Publication 1099
That distinction matters when checking an exchange's download menu. A document labeled with the tax year and the date it becomes available may display two different years without either being wrong.
Why a 2026 sale can still have missing basis
Bitcoin generally becomes covered when acquired after 2025 in a broker's custodial account and held there continuously until sale. Older purchases and transferred-in coins are noncovered, for which basis reporting is optional. These are information-reporting categories. 2026 instructions
For example, Bitcoin bought for cash in February 2026 and retained at the same broker until sale fits the basic covered pattern. A 2024 purchase deposited there this summer does not.
A blank basis field differs from zero. Brokers must leave it blank when omitting noncovered basis and enter zero only for actual zero basis. Box 1g instructions
Proceeds alone cannot establish the gain
For a cash purchase, basis generally includes the purchase price and qualifying acquisition transaction costs. On a subsequent cash sale, gain or loss depends on the amount realized and adjusted basis, with applicable disposition costs taken into account. IRS digital-asset transaction FAQs
In a simplified illustration with no fees or other adjustments, selling a Bitcoin lot for $9,000 after buying it for $7,000 produces a $2,000 gain. The $9,000 sale figure by itself cannot tell the reader that. This is why substituting the reported proceeds for taxable profit can produce a materially wrong result.
The 2026 lot-identification exception deserves attention
There is a current-year wrinkle beyond missing purchase data. Notice 2026-20 extends temporary identification relief through December 31, 2026, for digital assets held by a broker. Eligible taxpayers can identify the particular units in their own books by the transaction's date and time, or use a sufficiently detailed standing order recorded before the transaction. This is not permission to choose lots retrospectively when preparing a return. Notice 2026-20, sections 3–4
The notice also warns that the taxpayer's valid lot identification and basis can differ from the broker's reporting because the relief does not change the broker's information-reporting rules. Taxpayers using the separate Revenue Procedure 2024-28 allocation safe harbor must first satisfy its applicable requirements. Assets outside broker custody are outside this temporary relief. As written, it cannot be used for transactions after the relief period ends. Notice 2026-20
The practical consequence is to preserve the dated identification records alongside the statement, rather than assuming every mismatch proves a broker error.
Relief and repeal have specific boundaries
The IRS provides good-faith filing and statement-furnishing penalty relief for brokers' 2025 reporting. Separately, Notice 2025-33 extends brokers' backup-withholding relief through 2026. Neither announcement makes an individual's Bitcoin gains exempt from reporting. IRS transition summary, Notice 2025-33
The 2025 congressional repeal concerned the separate rule covering certain decentralized-finance participants. Treasury and the IRS removed that rule; it did not erase the custodial-broker framework described in the current Form 1099-DA instructions. IRS revocation of T.D. 10021
Keep the evidence behind the form
A useful reconciliation file retains acquisition and disposal dates, quantities, dollar values, basis, fees, and records linking transfers between accounts. The IRS's recordkeeping guidance calls for documentation sufficient to support the positions on the return. IRS digital-asset guidance
If a statement is incorrect, request a correction from its issuer and retain the correspondence. Missing forms do not remove the obligation to report taxable transactions, including those conducted through foreign brokers. IRS recipient guide
Form 1099-DA adds another piece of evidence. A complete transaction history remains what connects the sale proceeds to the basis and holding period of the Bitcoin actually sold.