can a collection agency charge you interest if they never notified you of the account?

Collection agency is a third party, you need to look to the original contract between you and the other party to see if outlined within who ever originate the claim, also if judgment is obtained one may also seek interest payments on amount due and owning from the courts as part of the judgment which could then be sold off to a collection agency

Usually a collection agency will take the case to court. They will try to setup a payment plan with you that you can afford. BUT this does not happen right away. Unfortunately the interest starts as soon as they receive the account! If you haven't received anything from them, call them and find out what's going on and resolve it before it gets to court. Good Luck

Collection agencies are subject to state laws, so you should check to see what they are in your state. Generally, though, they can and do charge interest, and are under no obligation to "notify" you of the debt, the presumption being that you surely knew of the debt long before it was turned over to collection. There are limits on when and where and how often they can contact you, and that will be useful for you to know!

They will, I hate them damn people. You call them and they act like they did this and they did that and knowing they lying. Someone took loans out in my name and by the time I found out they had added like $600 dollars on to it. If its not yours dispute your credit reports. Thats what I had to do and now someone owes me my income tax back.