Paying off debt and getting your credit card down to a zero balance account can be a huge feat. But if you’re not careful, it can be too easy to get right back into the same predicament.

For nonessential purchases, it is advisable to save up funds rather than rely on a credit card — even one with a zero-interest offer. Related: Do balance transfers affect your credit score?

If a credit card refund results in a negative account balance, the issuer will return the money. Alternatively, you could charge additional purchases to bring the balance back up to zero or more.