Can I deduct bills as business expenses when operating a business from home? -

My husband and I operate a small business out of our home. What portion, if any, of our bills are tax deductible as business expenses? I m talking about the mortgage, electricity, phone, etc...

Is it best that you talk to a CPA ( a certified public accountant) but I know that you can claim up to 40% of your home. (which means 40% of your mortgage) If you setup a separate phone and fax line you can also claim those as tax deductible expenses.