DH works out of a home office for a company. I did all the usual home office deductions on the tax return. According to the IRS: You can only deduct the amount of space you use in your house or apartment for your business. That means, if your office is one of ten rooms in your home, and the rooms are approximately the same size, then you can deduct one tenth of your rent, mortgage, property taxes, utilities, renter's or homeowners insurance, maintenance costs, and so on. My question is this: If I've already itemized on my Schedule A the property taxes and mortgage interest, I don't do it on the Form 2106 - Employee Business Expenses. I don't think I would for the property taxes and mortgage interest...is that correct? I've already itemized them on my Schedule A. I would however list a portion of my homeowners insurance on Form 2106-Employee Business Expense...is that correct. What about a portion of the mortgage, do I write off a percentage of the principal on the mortgage? I want to make sure we get all deductions coming to us for him working at the house now. Thanks all.