openrtb.seatbid.seat_not_allowed
What it means
The seatbid's seat is not permitted by the request: absent from its wseat allowlist, or present in its bseat blocklist. Seat restrictions are how publishers and deals scope which buyer accounts may participate.
Why it matters
A bid from a disallowed seat is discarded no matter its price, so the compute behind it was pure waste. Recurring violations look like a bidder ignoring deal terms, which sours the direct relationships seats exist to serve.
How to fix it
Filter eligible seats against wseat/bseat before bidding, and propagate the restriction into your campaign selection so restricted requests only reach campaigns from permitted seats.
Check your payload
Paste a bid request or response into the tester to see whether this code fires against it, or gate on the id in CI with the CLI: the id is stable, wording is not.
Back to the full diagnostic code reference.