Deductions & credits

On Page 32, Publication 334 states: "...Your workplace can be your home if you have an office in your home that qualifies as your principal place of business. For more information, see Business Use of Your Home, later"  This has always confused me (and I'm sure many others).

 

Here is the situation.  I am a sole proprietor in two separate businesses.  I use my personal vehicle and take the standard mileage deduction for both businesses.  For the first business, I do computer support, which includes driving to client's sites and then, usually, home.  For my second business I do Uber/Lyft driving.  For this business I normally go on-line with the Uber driver app from home and go off-line at the end of the day at my home. 

 

My question is: Do I need to have an actual "home office" (area only used for business, etc.) in order to claim my home as my place of business and, therefore, claim my vehicle expenses from and back to my home?