What evidence do auditors commonly ask for on A.3.25 Logging?

Log review process with periodicity or automated alerting, and records of reviews; PII access logging capturing actor, time, data subject and change; Access control and retention or de-identification procedure for logs; Processor criteria for customer log access and evidence of tenant separation in log access.

What is the most common gap auditors find on A.3.25?

Logs collected and never reviewed

ISO/IEC 27701:2025 · Annex A Table A.3 information security controls with PII-specific guidance

`A.3.25` Logging

The organization shall operate a process for reviewing event logs, either through ongoing automated monitoring with alerts or through manual reviews at a defined and documented interval, so that anomalies are spotted and fixes suggested. Where feasible, logs shall capture each access to PII: the person acting, the time, whose PII was involved, and any records added, changed or deleted. Where more than one service provider takes part in logging, their respective roles and any arrangement for accessing logs shall be set out in writing. Because logs may themselves hold PII, access to them shall be restricted so they serve only their intended use, and a procedure, ideally automated, shall remove or de-identify logged data in line with the retention schedule. A PII processor shall set, and publish to customers, the conditions under which it releases log information to them, including whether, when and by what means; and where customers can reach logs the processor manages, each customer shall see only entries about its own activity and shall be unable to alter them.

Source: ISO/IEC 27701:2025, A.3.25. The statement above is our statement of the clause, read from the published text and cited so you can check it against the official text, not the instrument verbatim. Open ISO/IEC 27701:2025 in the compliance library.

artefacts

held by a system

at each review

hard

to go live

Policy repository / GRC workspace

where the evidence lives

teal = a system already holds it · olive = produced at each review. To go live: easy when half or more of the artefacts are already held by a system, moderate from a quarter to a half, hard below a quarter.

These are the artefacts auditors commonly ask for on this requirement, our guidance rather than text from the standard. Your assessor decides what is sufficient in your context, and asks for samples across the period when a report covers one.

system holds itEvidence a system already holds

none for this control

periodic reviewEvidence produced at each review

none for this control

governing documentDocuments that govern the control

Log review process with periodicity or automated alerting, and records of reviews · Policy repository / GRC workspace
PII access logging capturing actor, time, data subject and change · Policy repository / GRC workspace
Access control and retention or de-identification procedure for logs · Policy repository / GRC workspace
Processor criteria for customer log access and evidence of tenant separation in log access · Policy repository / GRC workspace

First move

No system holds this evidence for you: it is people and documents. Reminders and routing to the owner still save time. Put the document under version control with an owner and review date, and log each review as a record with reviewer and date.

Common gaps auditors find

Logs collected and never reviewed
Access to PII logged at the system level with no record of whose PII was touched
Logs retained indefinitely with PII inside them
Customers able to see other tenants' log entries

Do this for your whole sheet

Paste the rows you run your controls from and get this mapping for every control at once, with the periodic-review ones flagged and a first move per row. No account for the first run.

Build my evidence sheet

A.3.24 Information backup · A.3.26 Use of cryptography