(WSYR-TV) — If you’ve ever been contacted by a collection agency over medical debt, you’re not alone. Over 40 million people have unpaid medical bills sent to collections. And get this: Almost half of those bills have at least one error. Before you make any payments, Consumer Reports has some advice on how to fight back against medical debt.

If you’re contacted by a debt collector for a medical bill you believe to be wrong, never pay it right away. Instead, CR says to take these steps.

Gather as much info as you can, including the name of the collection agency, the person you’re speaking with, their phone number, postal address, email address, and as much information about the bill as possible. 

There are a lot of scams out there, so doing this can deter any phony debt collector.

Next, ask the debt collector to send verification of the debt. You can expect to receive the information in the mail within about five days of your request.

If the verification letter shows an error, file a dispute in writing by either email or certified letter within 30 days or else the collection agency will assume the debt is valid. 

One more tip: There might be a statute of limitations on how long a debt can be collected. Do not pay any part of it until you’re sure you still owe the money.