EU AI Act Annex IV: Technical Documentation Requirements Explained

Annex IV of the EU AI Act defines the technical documentation requirements for high-risk AI systems. If your AI system is classified as high-risk under Article 6 or Annex III, you must produce and maintain documentation that covers nine specific areas. This documentation must be prepared before the system is placed on the market and kept up to date throughout its lifecycle.

Why technical documentation matters

Technical documentation serves two purposes under the regulation: it demonstrates compliance to authorities and it ensures that the organization itself understands its AI system well enough to manage risk. Regulators can request this documentation at any time, and insufficient documentation is itself a compliance violation carrying fines up to €15 million or 3% of global revenue.

The nine required sections

1. General description of the AI system

Document the system's intended purpose, the provider and deployer identities, the system version, how it interacts with hardware or software, and the forms in which it is placed on the market (SaaS, on-premise, API). Include any relevant previous versions and a description of the interaction between the AI system and any hardware or software that is not part of the AI system itself.

2. Detailed description of system elements

This covers the development process: methods and steps for building the system, design specifications, system architecture, computational resources used, and the key design choices. Describe the algorithms, the model architecture, the training methodology, and how the system processes inputs to produce outputs.

3. Monitoring, functioning, and control

Describe the system's capabilities and limitations, the degree of accuracy and robustness, known or foreseeable risks, human oversight measures, and the specifications for input data. Include the measures put in place to facilitate human oversight, including technical tools to interpret outputs.

4. Risk management system

Document your risk management process as required by Article 9. This includes the identification and analysis of known and foreseeable risks, estimation and evaluation of those risks, risk mitigation measures adopted, and residual risks with their acceptability rationale.

5. Data governance

Describe the training, validation, and testing datasets: the data collection process, data origin, the scope and main characteristics of the data, how data was prepared (labeling, cleaning, enrichment), assumptions about the information the data represents, and measures to detect and address bias.

6. Testing and validation

Document the testing and validation procedures used during development, including the metrics used to measure accuracy, robustness, and cybersecurity, the testing methodologies applied, test results, and the dates when tests were performed. Include any adversarial testing conducted.

7. Post-market monitoring

Describe the post-market monitoring system established pursuant to Article 72. This includes how you will continuously monitor the system's performance in production, collect feedback from deployers, identify emerging risks, and update the system and documentation as needed.

8. Standards and certifications

List any harmonized standards applied in full or in part, and describe the solutions adopted to meet the requirements of the regulation where harmonized standards were not applied or were only partially applied. Include any relevant certifications or conformity assessment results.

9. EU Declaration of Conformity

The technical documentation must include or reference the EU Declaration of Conformity, which formally states that the AI system complies with the regulation's requirements. This is signed by the provider and must be kept for 10 years after the system is placed on the market.

Common documentation mistakes

• Treating it as a one-time exercise. Documentation must be kept current throughout the system's lifecycle. Any significant change triggers an update.
• Being too vague. Regulators expect specifics — architecture diagrams, actual metrics, real dataset descriptions. Generic statements don't satisfy the requirement.
• Forgetting third-party components. If you use a pre-trained model or third-party data, you must document it and its characteristics.
• Ignoring residual risks. You must document risks you chose to accept and explain why they are acceptable.

How ActReady automates Annex IV documentation

ActReady generates Annex IV-compliant technical documentation using AI. You provide the details about your system — its purpose, architecture, data sources, and risk profile — and ActReady produces a structured document covering all nine required sections. Each document is generated based on your specific system details, not generic templates. You review, edit, and approve before finalizing. The entire process takes minutes instead of weeks.