Metal accounting – AMIRA code principles

Metal accounting is the process of measuring, recording, and reconciling saleable metal across mining and processing operations. The P754 AMIRA code defines 10 best-practice principles covering accurate measurement, transparency, audits, data verification, and governance, helping mining companies reduce financial risk, optimize plant efficiency, and improve inventory reporting.​ A concise, practical guide for metallurgists, process engineers and financial controllers to learn what metal accounting is, the 10 AMIRA P754 principles, and how to implement a compliant metallurgical accounting system. Last update on October 28, 2025.

• What is metal accounting?
• Why is metal accounting important?
• What is the AMIRA P754 code?
• What are the AMIRA P754 code principles (and a summary of the 10 principles)?
• How to implement a compliant metallurgical accounting system (like INVENTEO from CASPEO)?
• Frequently Asked Questions (FAQ)

What is metal accounting?

Why is metal accounting important?

Metal accounting is widely used to quantify the performances of production plants and to estimate as accurately as possible the metal inventory. The main benefits of a metal accounting system are :

What is the AMIRA P754 code?

What are the P754 AMIRA code principles?

The recommendations of the P754 AMIRA code can be summarized in ten main principles that INVENTEO, CASPEO metallurgical accounting solution, allows or helps to apply.

Here is the 10 principles of the AMIRA code for metal accounting (P754 AMIRA code and guidelines – release 3 February 2007):

Principle 1: Accurate measurements

The metal accounting system must be based on accurate measurements of mass and metal content. It must be based on a full Check in-Check out system using the Best Practices as defined in this Code, to produce an on-going metal/commodity balance for the operation. The system must be integrated with management information systems, providing a one-way transfer of information to these systems as required.

Principle 2: System consistency & transparency

The system must be consistent and transparent and the source of all input data to the system must be clear and understood by all users of the system. The design and specification of the system must incorporate the outcomes of a risk assessment of all aspects of the metal accounting process.

Principle 3: Documentation & procedures

The accounting procedures must be well documented and user friendly for easy application by plant personnel, to avoid the system becoming dependent on one person, and must incorporate clear controls and audit trails. Calculation procedures must be in line with the requirements set out in this Code and consistent at all times with clear rules for handling the data.

Principle 4: Regular audits & reviews

The system must be subject to regular internal and external audits and reviews as specified in the relevant sections of the Code to ensure compliance with all aspects of the defined procedures. These reviews must include assessments of the associated risks and recommendations for their mitigation, when the agreed risk is exceeded.

Principle 5: Timely reporting & investigation

Accounting results must be made available timeously, to meet operational reporting needs, including the provision of information for other management information systems, and to facilitate corrective action or investigation. A detailed report must be issued on each investigation, together with management’s response to rectify the problem. When completed, the plan and resulting action must be signed-off by the Competent Person.

Principle 6: Provisional data management

Where provisional data has to be used to meet reporting deadlines, such as at month ends when analytical turn-around times could prevent the prompt issuing of the monthly report, clear procedures and levels of authorisation for the subsequent replacement of the provisional data with actual data must be defined. Where rogue data is detected, such as incorrect data transfer or identified malfunction of equipment, the procedures to be followed together with the levels of authorisation must be in place

Principle 7: Data quality and reconciliation

The system must generate sufficient data to allow for data verification, the handling of metal/commodity transfers, the reconciliation of metal/commodity balances, and the measurement of accuracies and error detection, which should not show any consistent bias. Measurement and computational procedures must be free of a defined critical level of bias.

Principle 8: Target accuracy & recovery measurement

Target accuracies for the mass measurements and the sampling and analyses must be identified for each input and output stream used for accounting purposes. The actual accuracies for metal recoveries, based on the actual accuracies, as determined by statistical analysis of the raw data, achieved over a company’s reporting period must be stated in the report to the Company’s Audit Committee. Should these show a bias that the Company considers material to its results, the fact must be reported to shareholders.

Principle 9: Inventory verification

In-process inventory figures must be verified by physical stock-takes at prescribed intervals, at least annually, and procedures and authority levels for stock adjustments and the treatment of unaccounted losses or gains must be clearly defined.

Principle 10: Bias identification & elimination

The metal accounting system must ensure that every effort is made to identify any bias that may occur, as rapidly as possible and eliminate or reduce to an acceptable level the source of bias from all measurement, sampling and analytical procedures, when the source is identified.

The 10 AMIRA P754 principles in metal accounting (summary)

How to implement a compliant metallurgical accounting system? 

A compliant metallurgical accounting system serves as a comprehensive control framework across all metal production stages: mine, mill, concentrator, smelter, hydrometallurgical plant, and refinery. Its goal is to ensure every ton of metal is measured, validated, and reconciled through a standardized, auditable, and transparent process.

When effectively implemented, a metal accounting system provides a single, reconciled view of metal flows and recoveries, enabling operators to detect losses early, ensure reporting accuracy, and strengthen investor confidence.

 The main steps to implement a metal accounting system is:​ 

Step 1: Establish a solid data foundation

The starting point of an efficient metal accounting system is a precise understanding of the process operations from ore reception to final product.

The quality of raw data, mass measurements, moisture, densities and metal assays, is the foundation of an accurate metal balance. Every stage of the value chain must rely on an accurate sampling and measurement system, and robust data reconciliation.

To achieve consistency and traceability:

• Document all data sources, sampling protocols, and analytical methods.
• Ensure every measurement, even historical ones, is traceable and reviewable.
• Define procedures for data validation, especially for laboratory assays and production figures.

Step 2: Move beyond spreadsheets

While spreadsheets are still widely used in some operations, they are not compliant with AMIRA P754 requirements. The AMIRA Code clearly emphasizes that a metallurgical accounting system must be auditable, traceable, secure, and repeatable.

Spreadsheets, by their nature, fail to meet these criteria because they:

• Lack data security and version control, making it impossible to verify who changed what and when
• Are prone to manual errors in formulas, data entry, and references
• Offer limited traceability, with no automatic audit trails
• Do not support centralized validation or multi-user access
• Are difficult to integrate with plant systems (SCADA, LIMS, ERP), leading to data silos

As a result, relying on spreadsheets introduces significant compliance, accuracy, and governance risks.

Step 3: Deploy specialized metal accounting software

To ensure your metal accounting system is accurate, auditable, and compliant with the AMIRA P754 code, your implementation should be built on robust production accounting and reconciliation software, disciplined data management, and strong operational governance.

These systems allow you to:

• Centralize and reconcile process and production data
• Automate mass and metal balance calculations
• Apply AMIRA P754-compliant logic for data validation and reporting
• Provide dashboards and alerts for deviations or material losses
• Integrate seamlessly with SCADA, LIMS, and ERP systems

Such software not only ensure compliance but also improve operational efficiency, decision-making, and governance.

Step 4: Integrate across your data ecosystem

Connect your metal accounting platform with existing data acquisition and management systems. Automated data exchange eliminates manual handling, reduces latency, and ensures a single, reliable version of the truth across departments.

Step 5: Build a culture of accountability and training

Regularly train metallurgical teams, plant operators, and auditors on metal accounting procedures, data validation practices, and the AMIRA principles. Sustainable compliance depends as much on people as on technology, well-trained teams are key to maintaining accuracy, detecting anomalies early and adapt the system to your process evolution.

Frequently Asked Questions (FAQs) on metal accounting AMIRA code best practices