If you have a verified home office then all business mileage is deducible from the moment you leave your door. But if you ONLY have one client then it would seem like you should be an employee not a sub contractor.
You can take the office in
home expenses if you meet the "regularly" and "exclusively"
tests.
To deduct expenses related
to the business use of part of your home, you must meet specific requirements.
Even then, your deduction may be limited.
General Rules
To qualify to claim expenses for business use of your home, you must meet the
following tests.
1. Your use of the business part of your home must be:
------a. Exclusive (see below),
------b. Regular,
------c. For your trade or business, AND
2. The business part of your home must be one of the following:
------a. Your principal place of business
------b. A place where you meet or deal with patients, clients, or customers in
the normal course of your trade or business, or
------c. A separate structure (not attached to your home) you use in connection
with your trade or business.
Additional Rules For Employees
There are additional tests for employee use. If you are an employee and you use
a part of your home for business, you must meet the tests discussed above plus:
1. Your business use must be for the convenience of your employer, and
2. You do not rent any part of your home to your employer and use the rented
portion to perform services as an employee.
Whether the business use of your home is for your employer's convenience
depends on all the facts and circumstances. However, business use is not
considered to be for your employer's convenience merely because it is
appropriate and helpful. Also, if your employer provides you with office space
at the employer's location, it is very difficult to support that working at
home is for the employer's convenience.
Exclusive Use: To qualify under the exclusive use test, you must use a
specific area of your home only for your trade or business. The area used for
business can be a room or other separately identifiable space. The space does
not need to be marked off by a permanent partition.
You do not meet the requirements of the exclusive use test if you use the area
in question both for business and for personal purposes.
Where to Report:
This article discusses where to deduct it in Turbotax:
https://turbotax.intuit.com/support/iq/Deductions---Credits/Can-I-take-the-Home-Office-Deduction-/GE...
