[usr1106]

I don't want 5-10 minutes necessarily.

But what would be best practices for billing alarms? I have used them in the past when I used a bit more of AWS, but I don't think I ever got one (which is good).

But it happens to me that I miss emails that I would have liked to read in time for weeks. That could happen with a billing alarm, too.

Maybe you could forward it to SNS with SMS delivery. But as a matter of fact SMS is one of the few services (if not the only one) with a spending limit. If that is reached you silently won't get SMSes anymore, I have experienced that.