What happens if I hire a car OUTSIDE of London, and take it into the congestion charge zone?

What happens if I hire a car OUTSIDE of London, and take it into the congestion charge zone?

A:

If you hire a car outside of London, you will need to pay the congestion charge yourself, directly. Find out how to pay on TFL’s website. If you don’t pay, and we are served a fine, we will be required to pass this charge on to you.