Benefits in kind are classed as an income for tax reasons. You can imagine what a loophole it would be if they weren't.
If Andy's allowances are classed as a benefit in kind, then he will pay tax, and it will be declared on the P11 - along with a "value" of those benefits.
Makes it frankly a bit sickening if it isn't classed as income, because many companies class their benefits in kind as part of the overall wage package

There's no such thing as a free lunch, they don't give them for nothing.
Not all benefits though are taxed as income, such as car parking IIRC. I suspect fuel allowance and car maintenance isn't classed as a benefit, and more reimbursement. I really hope I'm wrong on that and it could help Andy, but......well time will tell