[danpat1]

I have a part time job plus 3 or 4 separate businessed at home; I have been thinking of prorating all - util, homerepair, upkeep, hskeeping; etc by 1 bus = 10%; 2nd bus = 10%; 3rd bus = 10% so taking 30% off house payment and everything else; may I do this or do I have to stick to square footage and if I do, I have a computer room, but work mainly in the family room, do packing there, also in garage-may I add all of these square footage(s) together can I claim like 30% of house payment since if I rented an office the rent would be allowable also.

[MukatA]

Your home office qualifies for deduction only if the space is exclusively for your business use.

Family room or garage used by other family members does not qualify.

To qualify to claim expenses for business use of your home, your use of the business part of your home must be exclusive, regular, and for your business. Also the business part of your home must be one of the following:
*Your principal place of business,
*A place where you meet or deal with patients, clients, or customers in the normal course of your business, or
*A separate structure (not attached to your home) you use in connection with your business.

You can deduct a percentage use of the Internet expenses, water and electricity expenses for home office.

[ScottGem]

I would be very careful about claiming a home office deduction. First, as Mukat stated, there are very specific rules for doing so. Second, doing so is often a flag to trigger an audit. And Finally, doing so means that part of your property is now commercial real estate which can have a effect when you want to sell. Just doesn't seem worth it for the small deduction you get.

[AtlantaTaxExpert]

You need to RUN (not walk) to the office of a tax professional who has experience filing returns with the home office deduction.

The complexities of such a return are such that you, as an amateur, could easily make mistakes that could cause multiple audits from the IRS and state tax departments.

Paying a tax professional the $300-$500 fee to prepare your return is money WELL SPENT for the headaches you would avoid down the road.

PLUS the fee is fully deductible on your Schedule C.