™The obligation, in plain terms
Article 16(6) of MiFID II requires investment firms to keep records of all services, activities and transactions undertaken, sufficient to enable the competent authority to fulfil its supervisory tasks and to perform the enforcement actions provided for in the Directive, including verification that the firm has complied with all obligations towards clients and prospective clients and towards the integrity of the market. The record set is not enumerated in the level 1 text. It is defined by the outcome: reconstruction.
Where the format lives: Commission Delegated Regulation 2017/565
Articles 72 to 76 of Commission Delegated Regulation (EU) 2017/565 and its Annex I set out the minimum list. The list is written for classical investment services (order reception, portfolio management, investment advice) but the retention and integrity obligations, in particular a five-year minimum retention period and durable-medium requirements, are read across to ancillary services and to instruments where the firm is acting as trustee, security agent or paying agent under a bond indenture.
What this means for a bond trustee
The supervisory question is: can the authority, from the records alone, reconstruct why the trustee acted, or chose not to act, on a covenant breach, a payment default, a security release, a waiver request, or a bondholder instruction. The evidentiary chain runs from the underlying indenture, through the trigger observation, through the assessment against the covenant text, to the decision and the notice served. Any gap in that chain is the compliance gap.
Deterministic records as a compliance primitive
A deterministic pipeline, one where the same input produces the same output byte-for-byte, satisfies the reconstruction test by construction. Every extraction from the indenture, every covenant check, every waiver decision is hash-chained to the input document, the ruleset version and the operator identity. The audit trail is not generated for supervisors, it is the operating record itself.
Retention and durable medium
The five-year minimum applies from the date the record is created or the transaction closes, whichever is later. Competent authorities may extend to seven years. Records must be stored in a form that prevents alteration, is readily accessible, and permits reconstitution of each key stage. Append-only ledgers with cryptographic linkage are consistent with the durable-medium standard.