Establish 'debt' is money you owe and 'credit' money you borrow. Before you borrow money, you should know how much you'll have to pay back, how you'll afford it and when you'll have to do it.
Out of curiosity, I took a bit of time to look up the earliest example of the phrase ‘a question of when, not if’ being used ...
Some results have been hidden because they may be inaccessible to you
Show inaccessible results