ISO 27001 × Fintech

ISO 27001 Audit Logging for Fintech

ISO 27001 certification is increasingly required by European banks and financial institutions before vendor onboarding. The 2022 revision (ISO 27001:2022) makes logging requirements more prescriptive than SOC 2.

Why ISO 27001 matters for fintech

European fintech buyers default to requiring ISO 27001 rather than SOC 2

Annex A.8.15 (Logging) and A.8.16 (Monitoring) are evaluated against documented evidence — not just policy

A.8.17 (Clock synchronization) and A.8.18 (Privileged utility programs) require specific log entries

ISO 27001 surveillance audits happen annually — log integrity must be maintained continuously

About ISO/IEC 27001:2022 Information Security Management

ISO 27001 is the international standard for information security management systems (ISMS). The 2022 revision reorganized controls into four themes: Organizational, People, Physical, and Technological. Audit logging falls primarily under Annex A control A.8.15 (Logging) and A.8.16 (Monitoring activities). Organizations must produce logs, protect them from tampering, and review them regularly. ISO 27001 certification is recognized globally and increasingly required for cross-border business.

Retention requirement: Organization-defined, typically 1-3 years (must align with risk assessment)

Events fintech must log for ISO 27001

All user account lifecycle events

All privileged access and admin actions

All security policy violations

All security incident detection events

All change management approvals

ISO 27001 logging requirements

A.8.15 - Logging

Produce, store, protect, and analyze logs that record activities, exceptions, faults, and information security events. Logging facilities and log information must be protected against tampering and unauthorized access.

AuditKit: Immutable hash chain logging with cryptographic tamper detection

A.8.16 - Monitoring Activities

Networks, systems, and applications must be monitored for anomalous behavior. Appropriate actions must be taken to evaluate potential security incidents.

AuditKit: SIEM streaming enables real-time anomaly detection and alerting

A.5.23 - Information Security for Cloud Services

Processes for acquisition, use, management, and exit from cloud services must include logging and monitoring requirements.

AuditKit: Multi-tenant isolation ensures cloud audit data is properly segregated

A.8.10 - Information Deletion

Information stored in systems and devices must be deleted when no longer required. Deletion events must be logged.

AuditKit: Structured event logging captures data lifecycle events including deletion with full context

How AuditKit helps fintech pass ISO 27001

Cryptographically tamper-proof logs

SHA-256 hash chains and Merkle tree proofs provide mathematical proof that audit records have not been altered. This is increasingly the standard mechanism for satisfying ISO 27001 log-integrity requirements — assessors no longer accept policy-only controls.

Tenant-isolated audit pipelines

Fintech platforms typically serve multiple customers from shared infrastructure. AuditKit enforces strict tenant isolation at the infrastructure level — your customers' audit data is logically separated, satisfying data segregation requirements common in ISO 27001 assessments.

SIEM-ready event streaming

Stream audit events to Splunk, Datadog, Elastic, or any SIEM your security team uses. ISO 27001 increasingly requires real-time monitoring, not just retained logs — AuditKit ships native streaming with at-least-once delivery semantics.

Built-in auditor viewer

The AuditKit React viewer gives ISO 27001 auditors a clear interface for evidence review — filtered queries, integrity verification UI, and exportable evidence packages. Cuts auditor request cycles by 60-80% in typical engagements.

Quick facts

ISO 27001:2022 contains 93 controls organized into 4 themes (reduced from 114 in the 2013 version)

Control A.8.15 explicitly requires protection of logs against tampering

Certification requires annual surveillance audits and recertification every 3 years

Over 70,000 organizations worldwide hold ISO 27001 certification

Frequently asked questions

Should a US fintech pursue SOC 2 or ISO 27001?

It depends on your buyer geography. US enterprises overwhelmingly require SOC 2. European and APAC enterprises overwhelmingly require ISO 27001. Many fintech companies serving both markets pursue both — and the audit logging infrastructure is largely the same.

What does ISO 27001 require for audit logging?

ISO 27001 Annex A control A.8.15 requires organizations to produce, store, protect, and analyze logs recording activities, exceptions, faults, and security events. Logs must be protected from tampering and unauthorized access. AuditKit provides cryptographic tamper protection through SHA-256 hash chains and Merkle tree proofs.

What audit logging do fintech companies need?

Fintech companies need comprehensive logging of financial transactions, user authentication, KYC/AML activities, permission changes, and system access. Logs must be tamper-proof (PCI DSS 10.5), retained for 5-7 years (SOX/DORA), and available for real-time monitoring (BSA/AML). AuditKit provides all of these capabilities with SHA-256 hash chains and Merkle tree proofs.

Related audit guides

ISO 27001 audit logging built for fintech

Tamper-proof audit trails that satisfy ISO 27001 requirements out of the box. Start from $99/mo.