You need to find out IMM. Do not ask us members of EO this is a problem and one you need answers to Yesterday!!!! Otherwise your getting the screw driver taken to ya.
They need to explaine to you how it works if you need a listing of all of the States fuel tax puchase the Rand McNally make a photo copy of the States Map (all 50) and write in the fuel tax in each State. This is how I know what each State charges vs looking it up in alpha order that they have. (Rand McNally) I tape this copy to the front and back of my Map. Any further deductions NEEDS a phone call with an EXPLANATION any deductions that come as a shock!.
Your a Business person, NOW RUN IT LIKE A BUSINESS, and not just as OH WELL I will ask else where. This is the difference between staying in business and not. Sorry for the Bluntness often the Truth Hurts.