Purview Auto-Labeling: New Limits and Admin Checks

Microsoft's October 19 Purview post reports a major increase in SharePoint and OneDrive auto-labeling scale: the daily tenant maximum is moving from 100,000 to 500,000 files, while simulations can include up to 20 million matched files, up from 4 million. The changes are rolling out, so check your tenant before changing capacity plans.

The figures come from Microsoft's auto-labeling troubleshooting playbook. Treat the higher values as tenant-specific service ceilings, not a promised processing rate.

What the October update changes

Microsoft says the increases are rolling out tenant by tenant. If your tenant still shows earlier limits, the rollout may not have reached it. The 500,000-file ceiling is shared by active SharePoint and OneDrive policies, and failures can reduce actual throughput.

Check readiness before widening a policy

• Confirm licensing and roles. The playbook lists an E5 or P2-tier license and the relevant Purview compliance or information-protection roles. Use least privilege for policy changes and content preview.
• Verify workload prerequisites. Check that sensitivity labels are enabled for SharePoint and OneDrive, the target label is published and in scope, audit ingestion is enabled for simulation, and your region supports the feature.
• Check the content mix. If PDFs are in scope, verify PDF auto-labeling is enabled. Microsoft notes PDFs can be skipped without a labeling failure when the setting is off.
• Inventory shared capacity. Estimate files across all active policies and account for overlapping sites, policy scope, and files that may fail or be skipped.

Use simulation as the rollout gate

1. Run or refresh a simulation after changing the label, rules, or scope. Compare matches against a small set of known files.
2. Let the service finish. The playbook says new policies can take about 24 hours to provision and simulations can take up to 24 hours. Avoid editing during a run; check status and completion time first.
3. Turn on a narrow scope first. Start with representative sites, document expected labels and exceptions, and expand only after owners approve the results.
4. Monitor labeling failures. Inspect the policy's failure summary and file-specific reason. Fix actionable causes such as unsupported or unpublished labels, protected files, invalid names, and quota issues; distinguish them from conditions Microsoft identifies as by design.
5. Keep evidence current. Use the coverage report while available after simulation and retain policy scope, results, approvals, and failure trends with the rollout record.

Practical administrator checklist

• Review Message Center updates MC1461154 and MC1469958 alongside the public playbook.
• Record the limits currently visible in your tenant.
• Verify license, region, label publication, audit, SharePoint/OneDrive integration, PDF setting, and roles.
• Simulate a representative scope, review matches, then activate a small approved pilot.
• Check failures and tenant-wide capacity before expanding policies or planning backfills.

For Microsoft's complete workflow and failure-code guidance, see the Purview auto-labeling playbook and the Microsoft Learn references below.