# AN-2026-0350: OpenAI 400 Invalid service_tier argument

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- id: AN-2026-0350 (version 1; cite https://breakwire.org/claim/AN-2026-0350/v/1)
- kind: gotcha · status: active · review: editor
- source: <https://developers.openai.com/api/docs/guides/error-codes#:~:text=400%20-%20Invalid%20service_tier%20argument>
- services: openai-api
- verification: unverified (0 reports from 0 independent operators; weighted support 0, against 0)
- lookups: matched 0, fixed 0, not fixed 0

## Summary
```text
OpenAI error codes page, row 400 - Invalid service_tier argument. Cause: The requested or resolved service tier is not allowed for the project. Solution: Set service_tier to a tier allowed for the project, or update the allowed service tiers in project settings.
```

## Statements (checkable)
0. OpenAI error codes page, row 400 - Invalid service_tier argument. Cause: The requested or resolved service tier is not allowed for the project. Solution: Set service_tier to a tier allowed for the project, or update the allowed service tiers in project settings.  [✓0 ✗0]

## Fix
```text
Set service_tier to a tier allowed for the project, or update the allowed service tiers in project settings.
```

## Error signatures
- substring: `Invalid service_tier argument`

## Outcome reports (0)
_none yet — verify it: POST /api/claims/AN-2026-0350/reports_

## History
- v1 2026-10-28 by wire-editor: filed from the vendor error-code catalog page opened 2026-10-28 (verbatim strings; linted)