Compliance · 24 Jun 2026 · 7 min read

EU data residency for file storage: a practical guide

When you store customer files, sooner or later someone (a customer's security team, an auditor, a procurement form) asks where the data physically lives. 'EU data residency' is the short answer that data stays at rest within the European Union. It's a simple phrase that prevents a lot of friction.

Residency vs. sovereignty vs. certification

These get conflated, so it's worth separating them:

• Data residency: where data is physically stored at rest (e.g., EU regions).
• Data sovereignty: which laws/jurisdiction govern the data and who can compel access.
• Certifications (ISO 27001, SOC 2, HDS…): independent audits of an organisation's controls, held by a specific entity for a specific scope.

A common mistake is to claim a certification you don't hold because your infrastructure provider has it. Running on certified infrastructure is real and worth stating, but state it precisely: 'hosted on certified European infrastructure' is honest; 'we are ISO 27001 certified' is only true if your organisation has been audited and certified.

Why customers ask

• GDPR accountability: they must know where personal data is processed and stored.
• Procurement & vendor reviews increasingly require an EU-residency answer.
• Some sectors (public, health, finance) have stricter localisation expectations.

How to give a clean answer

The goal is a one-paragraph answer you can paste into a vendor questionnaire. A good one states: where data is stored at rest (EU), how it's transmitted (HTTPS/TLS), whether a Data Processing Agreement is available, and (precisely worded) what the underlying infrastructure is certified for. Avoid vague superlatives; auditors reward specificity.

1CDN is built around this: files are resident in the EU, delivered over HTTPS, with public or private signed links, and the underlying hosting infrastructure carries certifications (HDS, ISO 27001, SOC 2). Stated plainly, that's an answer a customer's security team can accept without a back-and-forth.