---
title: "WORM Storage (Write Once Read Many) — Definition & Engineering Context"
description: "WORM (Write Once, Read Many) storage is a data storage technology that allows data to be written only once and prevents it from being deleted or modified — satisfying SEC 17a-4, FDA 21 CFR Part 11, and HIPAA audit trail immutability requirements."
canonical: https://erpstack.io/glossary/worm-storage
markdown_url: https://erpstack.io/glossary/worm-storage.md
publisher: ERPStack
---

# WORM Storage (Write Once Read Many)

> **Definition:** WORM (Write Once, Read Many) storage is a data storage technology that allows data to be written only once and prevents it from being deleted or modified — satisfying SEC 17a-4, FDA 21 CFR Part 11, and HIPAA audit trail immutability requirements.

## In depth

For financial institutions, healthcare providers, and government contractors, regulatory frameworks mandate that audit records cannot be altered or deleted — even by system administrators. WORM storage satisfies this requirement through S3 Object Lock, Azure Immutable Blob Storage, or cryptographic append-only log tables in PostgreSQL. Any attempt to modify or delete a locked object returns an error at the storage layer itself.

## How ERPStack applies this

We configure AWS S3 Object Lock policies in Governance and Compliance mode for all audit log exports, satisfying SEC 17a-4 and FDA 21 CFR Part 11 requirements for immutable record retention.

## Related reading

- [Immutable Audit Trail](https://erpstack.io/glossary/audit-trail)
- [PCI-DSS Financial Compliance](https://erpstack.io/glossary/pci-dss)
- [HIPAA Compliance](https://erpstack.io/glossary/hipaa)