Under what circumstances would I not have to pay my debt back?

Under what circumstances would I not have to pay my debt back?

You don't have to pay your debts back if you go bankrupt. All your debts get written off if you've got no assets or income, you pay nothing. Also if the debt is very old. If your creditors haven't contacted you for more than six years, the debt may be null and void. I recently had a client who'd had a credit card for twenty years. They couldn't remember signing the original agreement, and it's unlikely that after all this time the bank still has a copy.