Hi, After being told I underpaid in tax I checked my tax account and noticed some discrepancies with my company car benefit. First off the day I got the car was 1.5 months off. I've just got my employer to send a new p11d to fix this date. The second potential discrepancy is the value. My account shows a car benefit when "£987" I don't know if this is for the year, or month. The statement also shows my salary sacrifice amount as 0, but I sacrifice 866.87 every 4 weeks from source/gross pay. This 866 amount lined up with the amount quoted by our provider Tusker, who also takes BiK into account. Would this be correct, or do I need to inform my payroll to correct these too? I really don't understand what any of this means, but I don't want to be under/over paying on tax.