Welcome Valerie.
Who is the company? And why would they only guarantee to remove 80% of your bad credit?
Are they in good standing with the BBB?
Are they charging you upfront and if so, how much?
Sorry, I'm just leery of credit repair companies. Some are legit, but a lot aren't. Whoever they are, check into them before you give over your information. Also, a lot of repairing you can do on your own. It's really not that difficult depending on what you need to have removed.
Just my .02