Question about mileage and deducations related to storage unit

[Judy_Toomey]

Hello, I'm hoping someone has some insight for me! I work as a 1099 subcontractor installing residential real estate signs. In the past year, the housing market has gotten really hot here, and I have a lot of posts and panels in inventory. I'm thinking about renting a storage unit to keep everything tidy, instead of having my front yard look like a post factory! If I do so, can I write off the cost of the unit's rental? Also, when logging my mileage, I would of course go to the unit first to pick up whatever posts and panels I need for the day's work -- would this be considered my first stop? (I don't want to log my miles this way and then have them disallowed.) Thanks for any insight you can provide!

[Critter-3]

You are correct on both fronts ... rental unit is deductible and the business miles would start from that point ... driving from home to the storage unit and back is non deductible "commuting" miles. 

[Hal_Al]

You MAY be able to deduct the mileage to and from your home to the storage unit IF you home is your "principal place of business (POB)".

To deduct mileage, the home just needs to be the "Principal Place of Business".  It does not need to qualify for the Home Office deduction (the 'Regularly and Exclusively' rule does not apply).  
https://www.irs.gov/pub/irs-drop/rr-99-7.pdf
https://www.irs.gov/publications/p463/ch04.html

https://www.irs.gov/pub/irs-pdf/p587.pdf (page 3) POB defined