Another comment gave you the gist, but it's also worth noting they can give you control over how much can be debited, how often it can be debited, etc. You can

Another comment gave you the gist, but it's also worth noting they can give you control over how much can be debited, how often it can be debited, etc. You can even use them to make budgets for yourself. The leading provider that I know of for this is https://privacy.com/ https://privacy.com/