Car was sold which was used partially for business use, though I discovered that depreciation was not taken over years. How handle this?

[rburke477]

I used a personal car for some business use over 8 years.  I sold the car in 2017 expecting to pay tax on the accumulated depreciation from the business use portion of driving, each year using the mileage rate and number of miles to calculate depreciation.  
But then in looking over previous year's tax returns, I discovered that from the first year I entered the car the miles driven for business use (on Form 4562 Depreciation and Amortization) along with other items, the cost basis for the car was missing.  So, Form 4562 for each of the 8 years of records the miles and % business use is recorded, but it does does not include a depreciation dollar amount for each and every year.  
I recall from the application of depreciation to a residential rental property, that when a depreciated asset is sold, tax on depreciation is due, *even if the depreciation was not taken*.  Is this true in this case for the car also?  If so, is my remedy then to file Form 3115 Application for Change in Accounting Method necessary to recoup the lost years of depreciation, to bring them forward to the year of sale?  I am familiar with this form (as daunting as it appears, it is not). 
Thank you kindly in advance for your reply.

[CathiM]

When you use the mileage rate and number of miles for your vehicle deduction, the car is not depreciated separately on Form 4562. The IRS figures in depreciation as a part of the mileage rate. So that is why you are not seeing the depreciation from prior years. You don't need to make a correction.  

According to the IRS:

"The standard mileage rate for business is based on an annual study of the fixed and variable costs of operating an automobile. For automobiles a taxpayer uses for business purposes, the portion of the business standard mileage rate treated as depreciation is 25 cents per mile for 2017. See section 4.04 of Rev. Proc. 2010-51.

Click here to read more: 2017 Standard Mileage Rates - Notice 2016-79.