No, you don't need to amend your income tax return. It is important to answer all question if it applies to you, because credits and deduction can be denied if question/s pertaining to that credit or deduction was incorrectly answered. It may also trigger a red flag with the IRS. This is just an example total mileage driven entered was 20,000 and your personal mileage was none., answered no to the question "If another vehicle was available for personal use", If that was the case, don't do anything, wait until you receive a letter from the IRS, if any, then you can explain the error that was done.
The mileage usage is deductible as business expense, if standard mileage is used rather than actual expenses. You must record personal and business mileage either using a mileage book or mobile application.
