Code escrow is the deposit of source code with an independent third party. When a contractually defined trigger event occurs — such as the software vendor’s insolvency — the customer gains access to the deposited source code.
In an ISMS context, code escrow addresses the requirements of ISO 27001 Annex A controls A.5.19-A.5.22 (Supplier Relationships) and A.5.30 (ICT Readiness for Business Continuity). If your organization uses business-critical software from third-party vendors without owning the source code, the vendor’s failure could jeopardize operations. Code escrow mitigates this risk. The escrow agreement defines trigger events, currency of the deposited version, and verification processes (build tests of the deposited code).