What is it? The Fronting tool is used as an indicator to show if there is a chance of fronting within your policy. Fronting is when a low risk driver is listed as the policyholder, and the higher risk driver is named as an additional driver.
Why does fronting exist? Fronting is an easy way for customers to make their premiums cheaper. Insurance policies mostly rate on the policyholder. Likewise if business use is selected, this will only cover business use for the occupation of the policyholder.
How do I use it? The tool will display when business use is selected, and there is a discrepancy between the declared industries of employment for the policyholder and additional drivers:

Hit the down arrow to expand this tool:

In this instance, we can see a discrepancy between occupations for the Main driver and first additional driver.
You need to be thinking about the risk here. Given the fact a plasterer in the building trade is a higher rated occupation than a nurse in health care, it would be safe to assume there is no fronting in this instance.
However, you should always inform your customer that business use only applies for the policyholders industry. So for the above example, whilst there is no fronting, only the main driver (Andrew) and the second named driver (Roy) will be insured to use the vehicle for work.