Audit logging for SOC 2: build vs. buy
SOC 2 doesn't just want you to have logs; your auditor will sample a date range and test whether the logs are complete, tamper-evident, and retained correctly. That bar changes the build-vs-buy math compared to logging for internal debugging. Here's what it actually takes to satisfy CC7.2 and CC6.1 in-house, versus buying it.
The real cost of building SOC 2-grade logging yourself
This assumes you're building specifically to pass a SOC 2 Type II audit, not just logging for your own internal use.
| Line item | Building it yourself |
|---|---|
| Mapping to CC7.2 / CC6.1 | Time spent translating “monitor for anomalies” and “log access-granted and access-revoked events” into an actual event schema an auditor will accept as evidence, usually a few weeks of back-and-forth with whoever is running your audit. |
| Tamper-evidence for the audit period | A Type II audit covers a period, commonly 6-12 months, and your auditor will want assurance the logs from month one haven't been quietly edited by month six. That requires a real integrity mechanism, such as hash chaining, not just a database with timestamps. |
| Evidence packaging | When the auditor asks for evidence, you need to produce it in a form they can review, not just raw database rows. Building an export and evidence-bundle path is its own piece of work, separate from the logging pipeline itself. |
| 1-year minimum retention | SOC 2 doesn't mandate a single universal number, but a 1-year minimum is the common baseline auditors expect, to cover a full Type II period plus lookback. That has to be locked into your storage configuration before the audit period starts, not retrofitted afterward. |
| Re-running this every audit cycle | SOC 2 Type II is recurring, not a one-time certification. Whatever you build needs to keep working, and keep being explainable to a new or returning auditor, year after year. |
Where teams get stuck with a SOC 2 auditor
The most common auditor pushback isn't “you don't have logs,” it's “prove these logs weren't altered” and “why is this event missing a required field.” Auditors specifically probe for gaps between what CC6.1 and CC7.2 require, meaning login, logout, failed-auth, access-granted, and access-revoked events tied to anomaly monitoring, and what a general-purpose logging setup happens to capture.
When building SOC 2 logging yourself makes sense
If you already have a mature logging pipeline, a security engineer who owns SOC 2 evidence collection as an ongoing role, and enough lead time before your audit window, extending that pipeline with proper hash chaining and retention can be the right call. It's a harder position to be in three weeks before an audit with no tamper-evidence story yet.
Frequently asked questions
What does SOC 2 actually require for audit logging?
CC7.2 requires monitoring for anomalies that could indicate security events; CC6.1 specifically expects that login, logout, failed-authentication, access-granted, and access-revoked events are logged as the input to that monitoring. Auditors test both the logs themselves and whether they're tamper-evident.
How long do I need to retain SOC 2 audit logs?
A 1-year minimum retention is the common baseline, long enough to cover a full Type II observation period, commonly 6-12 months, plus the lookback window an auditor typically samples from. AuditRails retains SOC 2 logs for a minimum of 1 year by default.
Do I need a hash chain to pass a SOC 2 audit?
SOC 2 doesn't name a specific technology, but your auditor will test whether you can prove logs from earlier in the audit period haven't been altered. A cryptographic hash chain is the standard way to make that provable rather than just asserted.
Can I use AuditRails for just SOC 2 and add other frameworks later?
Yes. Starter Trails includes one framework chosen at signup, including SOC 2; Framework Trails and Compliance Trails let you add more frameworks self-service later without changing your logging integration, since the underlying event format doesn't change per framework.