Assuming you are filling out a T2125 Business statement for your professional income, you can enter these in the Business Use of Home Expenses (this appears after the Fixed Assets section:(
1. Enter the square foot area of the home office
2. Enter the square foot area of the entire home
3. Enter he full amount of your home expenses (utilities, property taxes, mortgage interest, maintenance, etc).
The software will automatically prorate the amount claimable for the home office. The amount claimed as a current year expense will be the lesser of the amount calculated and your net income after all other business expenses. Any remainder will be carried forward to next year.
