Hi,
You should provide the gross monthly salary sacrifice deduction figure you will be paying each month. This is the amount that will be deducted from your salary each month before tax. The P11D value is used to calculate the taxable benefit of the company car, but for the specific question about payments, the gross monthly deduction is what you need to provide.
If you require further clarification, you might want to consult with your employer’s payroll department to ensure everything is correctly reported or contact our Income Tax team for advice.
Income Tax: general enquiries
Thank you.