Calculating The Home Business Tax Deduction

By Susan Ward, About.com

If you run a home business, you'll want to be sure you deduct all the relevant home business expenses on your income tax.


However, although there are income tax deductions that are specific to home businesses, not all home businesses will qualify for these tax deductions. The CRA (Canada Revenue Agency) has stringent conditions that determine whether or not a home business owner can claim business-use-of-home expenses on line 9945 of the T1 tax form.


Who can claim the home business tax deduction?

You can only claim business-use-of-home expenses if your home is your principal place of business, or you use the work space in your home only to earn your business income and use it regularly to meet with clients, customers or patients. So you can't claim business-use-of-home expenses if you are conducting business somewhere else as well, or because you sometimes work on business matters at home.

How to claim the home business tax deduction?

If you meet the CRA requirements, you're ready to calculate your business-use-of-home expenses. Because you're doing business where you live, your expenses will be a percentage of your home expenses. It's easiest to calculate if you have a specific room set aside for business purposes, such as a home office. Then it's a simple matter to take the area of your work space and divide it by the total area of your house.

For instance, suppose you have a home office that is 10 by 10 feet in a house that's 1800 square feet. Then your calculation of allowable portion of business-use-of-home expenses would be: 100 divided by 1800 = 5%.

The next step in calculating the home business tax deduction is to apply this percentage to your allowable household expenses. You can deduct a portion of all your house expenses that directly relate to operating your business, such as your utilities, telephone, and cleaning materials. If you own your home, you can claim a portion of your house insurance, property taxes, and mortgage interest (although you can't claim the mortgage payments themselves.) If you rent your residence, you can claim a portion of the rent you pay.

In the example I've just given, let's say that I own my own home, and all the expenses I've just listed total $6800 for the fiscal year. Then 5% (my allowable portion of business-use-of-home expenses) of $6800 (my total home expenses) is $377.78, which is my total business use-of-home expenses claim on line 9945 of the T1 tax form.

 If you operate a part-time business out of your home, you have to adjust your business-use-of-home expenses accordingly. For instance, suppose you use part of your home to run a consulting business five days a week. To figure out your business-use-of-home expenses, you would calculate how many hours in the day you use the work space in your home for business purposes, divide that amount by 24 hours, and then multiply the result by the business portion of your total home expenses.


Using the same example used above, and operating the business from 9 a.m. until 5 p.m. five days a week, (7 hours a day), 7/24 hours x 100/1800 square feet x $6800 home expenses = $99.17.

However, in the example, the business is only operated 5 days a week, so I would then reduce the claim accordingly: $99.17 x 5/7 = $70.84.

You can't deduct an expense from an income you don't have. In other words, you can't use the business-use-of-home expenses to create a business loss, so your deduction can't be more than your net income before you deduct these expenses. If it's more, you can carry the amount of these expenses forward into the next year.

It may not seem like a lot, but when it comes to income tax, every deduction helps. If you run a home business and meet the CRA's definition of business-use-of-home, you'll want to be sure you claim the home business tax deduction on your income tax.


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