The Travel Rule requires crypto service providers to share sender and recipient identifying information for transfers above a set amount. The requirement originated in traditional banking under the U.S. Bank Secrecy Act and was extended to virtual assets by the Financial Action Task Force in 2019. It applies to regulated exchanges, custodial wallets and other intermediaries, but not to direct peer‑to‑peer transfers between unhosted wallets. Thresholds vary by jurisdiction; the United States sets $3,000, the European Union applies a zero threshold, and other countries set differing limits. When a transfer meets the threshold, the originator’s provider transmits the sender’s name, account or wallet identifier and, where required, additional data to the beneficiary’s provider through secure off‑chain messaging. The data are not recorded on the blockchain. A verification step ensures the receiving institution is legitimate before any personal information is sent. The uneven global adoption of the rule, known as the sunrise problem, creates enforcement gaps and raises privacy concerns because identity data are collected and shared among multiple entities. The scope of the rule for decentralized finance and self‑custodied wallets remains under regulatory review. Regulators continue to refine the framework, and its long‑term impact on crypto privacy and compliance remains unresolved.