What a pre-audit is, and when it pays off

2026-09-23 6 min readBy the ICS technical team

A pre-audit, also called a diagnostic audit, is an evaluation of your organization against the requirements of the ISO standard before the certification audit. It does not issue a certificate and it does not count toward certification. Its purpose is simpler and more practical: to tell you exactly where you stand, so the audit that does count holds no surprises.

What it is for

• To measure the real gap. Not what you think is missing, but what an auditor would actually find.
• To prioritize. Not every gap has the same weight. A pre-audit separates what would stop certification from what is a minor improvement.
• To plan with real dates. Once you know the size of the gap, you can estimate how long it will take to close it and when to schedule the certification audit.
• To reduce risk. Arriving at the certification audit with major nonconformities means delays, follow-up visits and extra cost.

When it pays off

There are two moments where it is especially useful. The first is at the very beginning, before starting the implementation, to understand how far you are from the standard and avoid building what you already have. The second is when the system is already implemented, one or two months before the certification audit, as a full rehearsal with enough time left to correct what appears.

What is reviewed

• Scope and context of the organization, and whether they are well defined.
• Documented information: that what exists reflects reality and is under control.
• Records: training, suppliers, indicators, complaints, corrective actions.
• Internal audit and management review: whether they were carried out and properly recorded.
• Legal and regulatory requirements that apply to your activity.
• The processes in practice, through interviews and observation on site.

What it delivers

A clear report of the gaps found, classified by importance, with a concrete explanation of what each one means and what is needed to close it. It is a working document: it tells you what to do on Monday.

How it differs from other audits

The internal audit is carried out by the organization itself and is a requirement of the standard. The certification audit is performed by an independent certification body and ends in the decision to certify. The pre-audit sits in between: an external, objective view that has no effect on certification, designed only to prepare you for it.