Can I deduct upgrades for my truck if they are business related? For example, truck bed liner and topper, rear sliding window so I can haul tools, lumber and keep dry.

Yes, those are depreciable capital improvements to your truck, and if you use your truck more than 50% for business, they are eligible for the Section 179 Deduction. You could elect to deduct their cost all in the first year rather than depreciate them.

But what if I use the standard mileage deduction?

If you're self-employed, no, you can't deduct or depreciate the upgrades if you're taking the standard mileage rate deduction. You have to choose between the standard mileage rate deduction or actual expense method.

Depreciation is included as part of the the standard mileage rate of 57.5 cents per mile. Depreciation is 27 cents of the 57.5 cents. 

• See Can I switch between the standard mileage rate and actual expense method?

If you're an employee, mileage is no longer deductible. See Can employees deduct commuting expenses like gas, mileage, fares, and tolls?

Hi, 

How would you label the truck cap and rails improvements? would they be fixtures and furniture, equipment, or vehicle?  thank you