Or is the mobile unit my place of work for the day no matter where it goes? I am not required to use my own car.
Please explain. Are you a W-2 employee? Or do you work as an independent contractor?
-W-2 employees cannot deduct job-related expenses on a federal return. Job-related expenses were eliminated as a federal deduction for W-2 employees by the tax laws that changed for 2018 and beyond.
W2. The IRS still allows for a deduction for work miles driven. Not commute miles however. This year for me a new wrinkle has been added. We also have a mobile office that will move from location to location. Sometime I ride on the unit sometimes I follow the unit. When I follow the unit, is that considered work miles that I can deduct or is the mobile unit " my office location"?
Does this make it any clearer?
No. There is no federal deduction for "work mileage" for W-2 employees. W-2 employees do not get any federal deductions for job-related expenses.
Your state tax laws might be different in AL, AR, CA, HI, MN, NY or PA.
If you live in a state that lets you deduct job-related expenses, the information will flow from your federal return to the state return, so enter it in Federal>Deductions and Credits>Employment Expenses>Job-Related Expenses