I bought a car in 2018 for $30,000 and the same year that car got totaled and I got $20,000 from insurance. Can I put $10,000 as a loss to my taxi business?

[MichaelL1]

If this vehicle was 100% business then you would show it a sale for $20,000.

If you took the standard mileage deduction, the vehicle cost would show 25 cents a mile as deprciaiton in computing the gain or loss on the sale.

You would show this as a sale of a business asset.