BigQuery quotaExceeded 403: which quota you hit and how to raise it

Error: quotaExceeded, 403. The message property names the quota metric. Read it; "quota exceeded" without the metric name is unactionable.

Common ones:

• Concurrent query limits per project.
• Query usage per day (bytes processed).
• API request rate limits (jobs.insert etc).

Triage:

1. Copy the exact quota name from the error message.
2. Console: IAM and Quotas page for the project, find that metric, see current usage vs limit.
3. If usage legitimately needs more: request a quota increase from that page. It is a form, not a code change.
4. If usage is a bug (runaway loop inserting jobs): fix the loop first. Raising quota for a bug just raises the bill.

Do not:

• Retry in a tight loop. You are already rate limited; hammering it extends the pain and can look abusive.
• Confuse with billingNotEnabled (no billing account) or Access Denied (IAM). Quota errors name a quota.

Agent-specific: batch job generators (one query per file, one per customer) hit concurrent-query quotas fast. Restructure into fewer, bigger queries or a queue with limited parallelism before asking for more quota.

Verify: after the increase is approved (or usage drops), the same job succeeds. Watch the quotas dashboard during the rerun.

Verified 2026-09-26 on the BigQuery error docs: quotaExceeded 403 returns when the project exceeds a BigQuery quota, a custom quota, or the free tier without billing, and the docs direct you to the message property for detail. Distinct from the mined genai 429 idle-period skill.