It's a way of finding out how likely you are to be accepted for the finance agreement for your lease, without impacting your credit score. You give us some basic information and we tell you your chances of being accepted as a percentage based on our checks. The checks we do will be invisible to anyone other than you (and us), so they won't be considered by other lenders.
We can't be absolutely certain whether you will or won't be accepted until we run a full check when you apply for a lease with us (sometimes known as a hard check), but this 'soft' check will give you an idea of your chances.
You can more information about the things that could affect your chances of being accepted for finance from the Money Advice Service