Your ISO certificate is valid for three years after your initial issue date. Recertification requires you to undergo an audit similar to the initial auditing process without the need for a stage one audit.
This audit explores the same areas as surveillance audits, only looking more deeply into the holistic, National and Global implications of your implementation strategy. It reviews the whole of your processes and systems from beginning to end alongside investigating your continued commitment to continual improvement.
In short, the auditor will perform a thorough examination of every aspect of implementation before issuing certification with a strategic assessment plan that underlines the next certification cycle.