Salary + Car Allowance = Total Income?

Hi, I've looked to lease a car via my employers NHS Fleet Solutions contract however it has been rejected by Payroll as I input my total income per annum (annual salary + car allowance). They've advised I cannot add these together as an annual income and I have to use my base annual salary alone and ignore car allowance as HMRC 'do not count it in the calculation for NMW' which has confused me. I'm being taxed under a 1257L code on both so assumed as I'm being taxed at the same rate I could apply with my total income. Does anyone know how it works? Thanks for reading.

Hi ,
 

If you are in receipt of a car allowance from your employer it would go through payroll. You would need to speak to your employer as if this is not a contractual payment it may be why the employer is not including it. Unfortunately this situation is betweeen your employer and yourself. Thank you .