For Christmas shoppers that signed up for those buy now, pay later plans, the holidays are over and it’s time to pay up—maybe more than you expected. So Consumer Reports is here to make sense of these short-term loans with important advice on how to dodge costly fees and what to do next time.

Some of the plans offer no-cost or low-cost terms up front, but now that those gifts have been opened and payments are due, be careful. They can get very expensive if you miss a payment or are not paid in full when the promotion period ends. Late fees can range from a few dollars up to 25 percent of the loan amount. 

Payments that are made late, which is 30 days or more, might get reported to the credit bureaus and negatively affect your credit score.

Next time, Consumer Reports says there might be better options than buy now, pay later plans. 

First, look inside your wallet. Especially for expensive purchases, or if you think you might return something, consider using a credit card instead. Aim to pay the balance off as quickly as possible. You may earn reward points, and will have consumer purchase protections in case you have trouble with the merchant or the item you purchased. Buy now, pay later loans usually don’t offer protections.

If you don’t have a credit card, talk to your bank or credit union. Or if it’s a larger purchase, consider a personal loan. Interest rates average just under 11 percent for a three-year loan.

Finally, if you decide to buy now and pay later, see if you can pick the traditional pay-in-four plan. That’s when you’ll make four payments over six weeks with no or very small fees as long as you pay on time. And no matter which plan you pick, autopay ensures your bill is always paid on time. 

One more caution about buy now, pay later: Returns can be a hassle since you sometimes have to contact the seller and lender before you can stop making payments, a process that can take several weeks.