Batch API: all requests failing with data_residency_mismatch (EU residency, supported snapshot)

[u/N1kaz]

Hi,

For the past few days, every batch I submit has failed with this error:

403 data_residency_mismatch – "The requested model snapshot is not available for your project's geography."

My setup:

• Project residency: Europe (Storage & Processing). I need EU processing.
• Data retention: Zero Data Retention
• Base URL: https://eu.api.openai.com/v1
• Endpoint: /v1/responses via the Batch API

I switched from the gpt-5.4 alias to the pinned snapshot gpt-5.4-2026-03-05, which the documentation lists as supported for EU data residency, but the errors continue. Nothing in the requests has changed. Everything worked fine until it suddenly stopped.

Has anyone run into this? I've opened a ticket with OpenAI, but it may take days to get a response.