The payment limit is set to $100 by default. (I think it was already there when I first joined HF.)
Changing this should be sufficient for personal use.
Detailed limits for the Inference API can apparently be set for Enterprise subscriptions. Well, if multiple people are using it, it’s more convenient to have separate limits for each service.
Individual on/off settings for Inference Providers can be configured on the settings page.
Edit:
The payment limit is set to $100 by default
Oh… It was wrong…