live beyond (one's) means
To spend or owe more money than one is earning or is able to repay. They've been living beyond their means for some time now, but they're too proud to move out of that giant house or give up their expensive cars. Being so poor during college taught me not to live beyond my means once I got a steady job. If you keep living beyond your means, you'll deplete your bank account before you know it.
live beyond/within your ˈmeans
live on more/less money than you have or earn: They seemed wealthy but they were living well beyond their means.I find it very hard to live within my means.