Build the register in a spreadsheet
Export what you have, edit it, and upload it back. Rows match on their reference, so re-uploading updates rather than duplicating.
AI systems
Include the ones bought off the shelf and the ones a team adopted without asking. An inventory that omits shadow AI is where an auditor finds the gap.
No AI systems recorded yet
Asset register
Annex A.4. Data, models, tooling, compute, people and third-party services. Risk treatment plans are written per asset, which is why this is a register and not a paragraph.
No assets recorded yet