Crypto Tax Lots Enter Broker Reporting, but DeFi Stays Manual

Since January 1, 2026, U.S. custodial brokers have had to report basis for certain newly covered digital-asset lots, as USDC recorded $21.5 trillion in on-chain volume during the first quarter, up 263% year over year, according to Circle’s May 11 results. That observed volume is not a count of taxable trades—transfers, bots and settlement inflate it—but it shows why assigning basis after the fact no longer scales.

What is a crypto tax lot?

A crypto tax lot is a group of units acquired together with the same purchase date, cost basis and holding period. When part of a position is sold or exchanged, the selected lot determines the gain or loss: proceeds minus that lot’s adjusted basis. Fees allocated to an acquisition can raise basis; transaction costs allocated to a sale can reduce proceeds.

Specific identification lets an owner choose which eligible units leave first. That can preserve long-term holdings or realize a chosen gain or loss. Without adequate identification, the IRS generally applies first-in, first-out, assigning the earliest units in that wallet or account. Average basis is generally unavailable for ordinary crypto assets; the 2026 Form 1099-DA instructions reserve it for qualifying tokenized securities.

How does Form 1099-DA change lot selection in 2026?

Form 1099-DA makes basis visible for some broker-held assets, but it does not create a complete portfolio ledger. Brokers began reporting gross proceeds for 2025 transactions. For 2026, basis reporting applies to covered units generally acquired from and held with the same broker from January 1, 2026; older deposits and assets transferred from elsewhere can remain noncovered.

A customer must give the broker an adequate lot instruction at or before the sale. Otherwise, the broker generally reports the earliest units as sold. Customer-supplied acquisition details may help select a transferred lot, but current IRS instructions say brokers cannot use those details to report its basis or acquisition date.

The operational minimum is therefore:

• Store asset, units, acquisition time, wallet or account, basis, fees and transaction hash.
• Carry basis and holding period through transfers between accounts under common ownership.
• Record specific identification before execution and retain the broker’s confirmation.
• Reconcile every 1099-DA against the internal ledger instead of treating the form as complete.

Why do wallets and bridges still break the record?

Self-custody and cross-chain activity remain outside any single broker’s field of view. Moving an asset between wallets owned by the same taxpayer is generally not taxable, although tokens spent for transaction services can create separate gains or losses. An exact USDC route to Base, for example, can cross chains without giving the destination platform the original acquisition record. A swap into a materially different token is a disposition; whether a particular wrapped or bridged representation qualifies requires transaction-specific analysis.

The wallet-by-wallet rules in effect since 2025 make this separation consequential. For an unhosted wallet, specific units must be identified in the owner’s books no later than the transaction time, with records showing that those units left that wallet. The blockchain proves movement, not ownership, tax basis or the intent behind a lot selection.

What should crypto operators change now?

Operators should treat tax-lot state as part of trade execution, not annual reporting. The benefit is deterministic gain calculation and cleaner broker reconciliation. The cost is wallet-aware event sourcing, historical price evidence and controls for transfers, fees and failed transactions.

The first measurable test arrives in early 2027, when brokers furnish basis-bearing Forms 1099-DA for covered 2026 sales. The discrepancy rate between those forms and wallet-level ledgers will show whether the new reporting layer reduces uncertainty or merely exposes missing records.