If you want to avoid the most common mistakes I see with owner-operator tax returns, you need to get involved in checking the major numbers your tax preparer is using. Doing this can save 
Here’s the worst mistake I uncovered in a tax review this year. Though the return had been prepared by a trucking specialist, the husband-wife team had a feeling something wasn’t right and questioned the preparer about it repeatedly.
The couple had shown a net operating loss on their Schedule C for seven years. The only reason I’ve ever seen for a net operating loss is high depreciation. The problem with their most recent tax return was that there was less than $1,500 in depreciation.
The preparer, following settlement sheets that separated mileage pay from fuel surcharge pay, was including only mileage revenues in the gross numbers. Fuel surcharge payments were listed under “reimbursements,” which is not standard accounting practice.
So gross revenue was less than $100,000 each year, even though the per diem showed more than 250 days on the road each year. This is an absolute giveaway that the gross revenue is incorrect.
This mistake resulted in under-reporting income by $20,000 to $40,000 per year for seven years. Tax was underpaid by $3,500 to $7,000 per year. With interest and penalties, the liability could be as high as $75,000.
Here’s what you can do to avoid such situations:
