The 10% is the interest that the bondsman charges you.

So let's say that you have a bail set at $100,000 and you don't have it in the bank. You have multiple options.. You can get your friends and family to come together and help you out and come up with that $100k. Chances are you're not going to be able to do that. You can try to get a loan from the bank. Chances are you're not going to be able to do that either because banks will more than likely deny you a loan for bail. Plus, you're in holding. So you're not going to have access to a lender at a bank. Plus, loans through banks take a few days to come through. That's too long for most people.

So the only option left is to get a private loan. Well, where can you get a private loan that can loan you the money right away within the hour? A bondsman.

He loans you the money by paying the court directly. The court holds that money in escrow. You're released from holding with the promise that you appear in court.

The bondsman charges you 10%, or $10K for loaning you that money. Why so much? It's a privilege that you're paying for to not be in jail for a few days or weeks.

If you appear in court, the bondsman gets his $100K back, and he makes $10K on top of that.

If you fail to appear in court, the bondsman doensn't get his $100k back, AND he loses his $10k profit. That means he lost $110k. He's not going to be very happy about that. He'll send a bounty hunter after you. Or he could go after your belongings.

If you pay the $10k AND skip out on your court appearance, the bondsman still lost his $100k, but since he got $10k from you, he only had a net loss of $90k. Which is still alot, and he'll still send a bounty hunter after you or go after your belongings.

In some cases, if a bail is small enough, you may put something up as collateral like a car, or your house. That way, if you fail to appear in court, the bondsman can take your car or your house.