The Form 1099-DA has a box that asks to check if the broker relied on customer-provided acquisition information. When the IRS released the very first draft of Form 1099-DA in April 2024, Box 8 served a completely different purpose. It was originally used to report specific types of non-cash proceeds. However, after the final regulations for custodial broker reporting were published in June 2024, the IRS issued an updated draft of the form in August 2024. In that updated draft, the IRS completely repurposed Box 8 to its current function: indicating that the broker relied on customer-provided acquisition information. When a broker checks Box 8 (Broker relied on customer-provided acquisition information) on Form 1099-DA, it signifies that the exchange did not have independent, verifiable records of the asset's original acquisition date or cost basis (often because it was a "noncovered" asset transferred into the exchange from an external wallet). By checking this box, the broker is explicitly telling the IRS: "We are reporting the cost basis and acquisition date on this form, but we got these numbers directly from the taxpayer, not from our own internal custodial ledger." Under the final regulations, taxpayers are allowed to provide brokers with acquisition information for transferred-in assets. If the taxpayer successfully provides this data (and the broker accepts it), the broker will report the basis on the 1099-DA and check Box 8. Box 8 acts as a flag for the IRS. It signals that while the basis is reported on the form, it is ultimately based on the taxpayer's own external records. If audited, the taxpayer (not the broker) will bear the burden of proving that the customer-provided basis was accurate. This reinforces why maintaining your own independent transaction history and basis tracking across all wallets remains essential, even as exchanges begin issuing these forms.