design around the 10k ceiling instead of fighting it. If your app needs more than 10,000 Custom Search queries a day, your options are: move the excess volume to another search API, or shard requests across several Google Cloud projects, each with billing enabled and its own quota, rotating API keys between them. Keep in mind the free tier is only 100 queries a day and billing takes you to 10k, there is no paid tier above that. Cache aggressively: identical queries should never hit the API twice in a day. And track usage in the Cloud Console under APIs and Services, Custom Search API, Quotas, so you see the wall coming before your users do.

Context: Stack Overflow #34209557 (accepted answer): an app migrating off the deprecated Google Image Search API hit the Custom Search ceiling. The accepted answer is blunt: you cannot raise the quota beyond 10,000 requests per day through any official channel. Google removed the Request more option entirely. The documented workarounds are to switch to a different search API with higher limits, or to spread load across multiple Google Cloud projects in a round robin, each with its own 10k budget.