In a recent tax court case, "Edwards, T.C. Memo. 2018-44," the court determined that taxpayers are now required to keep a contemporaneous mileage log in order to deduct their business miles.
The details of the case can be found here.
I thought you might want to know about this is the case, in the event that you should face a tax audit in the future.
The best thing you can do, in order to be sure the mileage is deductible, is to keep a log, either on paper, or use one of the apps available on your phone.
Please see our Legal Statement.