Luxembourg publishes CARF XML reporting manual and schema

Prepare the reporting data

The guidance supports the Law of 27 March 2026 on the automatic and mandatory exchange of information reported by cryptoasset service providers, published as Mémorial A144. The ACD’s accompanying page says reporting starts with the 2026 calendar year and covers reportable users and aggregated cryptoasset transactions. Luxembourg-established reporting providers must submit the information, or a nil report, by 30 June of the following year.^[2]

The manual describes manual XML submission through MyGuichet or automated submission through an internet API. Validation checks include syntax, data consistency and compatibility with earlier submissions. A rejected return must be corrected and resubmitted with a new unique message identifier. Where linked data is split across files, submission order matters.^[3]

Technical publication is not operational activation

The announcement says examples and instructions for transmitting returns through secure state platforms will follow, alongside a MyGuichet registration guide. The CARF page also says registration and data-transfer procedures will be communicated later. Providers can prepare data and validation controls from the specification, but should not infer that every submission route is already operational or that the manual creates a new deadline.^[1][2]

The ACD distinguishes registration of cryptoasset operators from providers subject to the separate MiCA regime. Groups should check the relevant entity category rather than assume one registration process applies to all providers. This short update concerns the technical publication; it is not a full review of the underlying legislation or an independent test of the released XSD.^[1][2]