AWS enforces London-only data residency for Claude Code via Bedrock profiles

AWS's classic cross-Region inference (CRIS) is designed to smooth throughput, increase capacity, and provide early access to newer models by routing requests flexibly across multiple regions. However, regulated organizations—particularly in financial services, healthcare, and government—often face compliance requirements that specify exact geographic boundaries for data processing. The guidance acknowledges this tension: for most workloads, cross-Region is the right default, but the post provides two distinct patterns for organizations where a compliance team has "drawn a hard line" on a specific Region.

The choice between the two paths hinges on Regional availability. Mantle, Anthropic's native API shape running on Bedrock, is the newer, simpler option where it is available, offering direct single-Region routing without extra AWS infrastructure and access to newer models (Sonnet 5, Opus 4.8, Haiku 4.5). For London, however, Mantle offers only Global and EU endpoints—meaning a request from London could still be processed in Frankfurt, Ireland, or Paris. This cross-EU routing is exactly what the customer in the article needed to prevent. Classic Bedrock becomes the only option, though availability is narrow: only Claude Opus 4.6 and Sonnet 4.6 currently support in-Region inference in eu-west-2.

Both paths rely on IAM Region conditions to enforce the boundary. The IAM policy is the actual guardrail: even if a developer misconfigures an environment variable, the policy rejects requests outside the target Region. This pattern applies to any tool targeting an Amazon Bedrock model ID, making it a reusable template for compliance-driven deployments beyond Claude Code.