What "data residency" actually means (and the marketing copy to ignore)
Procurement teams routinely conflate three things under the same phrase. **Billing residency** — your invoice comes from an EU entity, your contract is governed by Irish or Dutch law. This is the cheapest version to provide and the least meaningful to a regulator. **Storage residency** — customer metadata, account config, audit logs, and any cached prompts sit on disks physically located in a specified region. **Inference residency** — the GPU that runs the forward pass on your prompt sits in the specified region. Only the third matters for GDPR Article 44 transfer analysis, German BfDI guidance on US cloud providers, and FedRAMP boundary definitions.
**OpenAI direct** publishes its enterprise privacy commitments at https://openai.com/enterprise-privacy/ and now distinguishes between US default routing and the EU data residency option for ChatGPT Enterprise, ChatGPT Edu, and the API. Inference for the EU residency tier runs on EU-located infrastructure; without that opt-in, prompts and completions are processed in US data centers. The default is US, and most teams that signed standard OpenAI contracts before mid-2024 are still on US default routing whether they realize it or not.
**Azure OpenAI** does residency the simplest way: the resource you create is region-locked. A resource created in `swedencentral` runs inference in Sweden, stores associated metadata in Sweden, and returns errors if you accidentally call a global endpoint. Per https://learn.microsoft.com/en-us/azure/ai-services/openai/concepts/models the per-region model availability matrix tells you which exact GPT, o-series, embedding, and image model you can call from each region — a moving target month-to-month.
**AWS Bedrock** also region-locks by endpoint — `bedrock.eu-central-1.amazonaws.com` runs inference in Frankfurt — but adds a twist with cross-region inference profiles introduced in 2024, where Bedrock can route requests across multiple regions for capacity. You have to explicitly disable cross-region routing if you need hard residency. Documentation at https://aws.amazon.com/bedrock/ and the AWS regional services list spell out which Claude, Llama, Mistral, and Titan models are GA in which Bedrock region.
**Google Vertex AI** offers three modes documented at https://cloud.google.com/vertex-ai/generative-ai/docs/learn/locations: region-locked endpoints (one specific region), multi-region endpoints (which stay within a continent — the `eu` multi-region stays in EU member states), and the global endpoint (which can route to any Google region including the US). For EU procurement, the `eu` multi-region is usually the right answer — it gets you capacity flexibility without crossing the Atlantic.
**Anthropic direct** documents its supported regions at https://docs.anthropic.com/en/docs/about-claude/regions and supports both US and EU inference for direct API customers. Workspaces are configured to a region at creation time and zero data retention is the default for direct API customers per https://www.anthropic.com/legal/commercial-terms. The practical upshot: Anthropic direct is now a credible EU vendor where it was US-only as recently as 2023.