If you are unsure of what to do, get help. Most initial consulting visits to accountancy firms are free. Do your homework, choose someone with a recognized accounting designation for assistance, and put all your questions in writing.Just take a quick look around your home. If you have a room set aside as an office; if you have furniture and equipment, computers, phones, a car and employee relatives, chances are you have things you can write off to maximize business tax deductions.
In the U.S. you can write-off a percentage equivilent to how much the space is used for business. So, if your workspace is 20% of your apartment and you use that 20% only for your business, then you can write off 20% of your rent, 20% of your electricity and other utilities. But if you only use that 20% of space for business 50% of the time for business and 50% for other purposes, you can only write off 10% and so on. The same is true for services such as your mobile. If you use it 10% of the time for personal and 90% for business you can write off 90% of the bill.I am not a tax professional. You should definately consult one for a definitive answer
-------------------------------------------------- Canadian mortgage
The rules for a home office have been changed since I started my consulting business 10 years ago. The conditions for deductability are as follows;You can deduct expenses for the business use of a work space in your home, as long as you meet one of these conditions:it is your principal place of business; or you use the space only to earn your business income, and you use it on a regular and ongoing basis to meet your clients, customers, or patients. You can deduct a part of your maintenance costs such as heating, home insurance, electricity, and cleaning materials. You can also deduct a part of your property taxes, mortgage interest, and capital cost allowance. To calculate the part you can deduct, use a reasonable basis such as the area of the work space divided by the total area of your home.If you use part of your home for both your business and personal living, calculate how many hours in the day you use the rooms for your business, then divide that amount by 24 hours. Multiply the result by the business part of your total home expenses. This will give you the household cost you can deduct.If you run the business for only part of the week or year, reduce your claim accordingly.see CRA web-page below