live paycheck to paycheck
To spend all of the money one earns by or before the next time one is paid, thus saving none or very little in the process. Primarily heard in US. We're already living paycheck to paycheck, so I don't know how we'll manage this sudden increase in our rent.
above (one's) paycheck
Beyond one's level of authority or expertise. I would love to sign off on those documents for you, Jim, but that's above my paycheck. Gina can't decide if we get interns this summer or not—that's above her paycheck!