The Home Office Deduction: Corporation vs Sole Proprietor

Canada has two separate home office regimes, and which one applies to you depends on whether you are self-employed or an employee - including an employee of your own corporation. Both use the same two-branch test, both cap the deduction at your income from that source, and both let you carry the unused portion forward indefinitely.

The 60-second version

Self-employed: subsection 18(12) of the Income Tax Act governs. Incorporated owner-manager: you are an employee, so subsection 8(13) governs instead.[1][2]
The test has two branches, and you only need one: the space is your principal place of business, or it is used exclusively for earning income and used on a regular and continuous basis for meeting clients or customers.[1]
It cannot create or increase a loss. The deduction is capped at your income from that business or employment before claiming it.[1]
Nothing is wasted. Any amount denied only because of the income cap carries forward and is deductible in a later year.[1]
Employees need a signed T2200 from the employer. The temporary flat rate method from the pandemic years does not apply to 2023 or later.[3]

Two regimes that look identical and are not

Read side by side, subsections 18(12) and 8(13) are near-mirrors. That is deliberate - Parliament wanted the same policy for both groups. But the differences are precisely where the money is.

Subsection 18(12), for a self-employed individual, denies a deduction for any part of a self-contained domestic establishment in which the individual resides, except to the extent that the work space is either (i) the individual's principal place of business, or (ii) used exclusively for the purpose of earning income from business and used on a regular and continuous basis for meeting clients, customers or patients of the individual in respect of the business.[1]

Subsection 8(13), for an employee, denies a deduction except to the extent the work space is either (i) the place where the individual principally performs the duties of the office or employment, or (ii) used exclusively for the purpose of earning income from the office or employment and used on a regular and continuous basis for meeting customers or other persons in the ordinary course of performing the duties.[2]

Note that second branch. For the self-employed it is "clients, customers or patients." For employees it is "customers or other persons," which is meaningfully broader - it can cover people you meet in the course of your duties who are not customers at all.

The word doing the heaviest lifting in both is exclusively, and it only appears in branch (ii). If your space is your principal place of business under branch (i), exclusivity is not required by the statute. A desk in the corner of a room can qualify under branch (i) on a reasonable apportionment. It cannot qualify under branch (ii), because branch (ii) demands the space be used exclusively for earning income.

Most home-based businesses qualify under branch (i) and never need to think about branch (ii) at all. Branch (ii) exists for the person whose principal place of business is elsewhere - a consultant with a downtown office who also sees clients in a dedicated home consulting room.

The cap, and why it is not a loss

Both provisions limit the work space deduction to your income from that business or employment for the year, computed without reference to the work space amount.[1][2] In plain terms: home office expenses can reduce your business income to nil. They cannot push it below nil.

This is the rule people misread as "you lose it." You do not. Paragraph 18(12)(c) - and its twin, paragraph 8(13)(c) - deems any amount not deductible solely because of the income cap to be an otherwise deductible amount in the immediately following year.[1][2]

And because the carried-forward amount is itself subject to the same cap in the next year, it chains. A denied amount rolls forward year after year until there is income to absorb it. There is no expiry.

The practical implication for a business in its early years: claim the full home office amount anyway. Track the denied portion. A start-up running at break-even for three years builds a real deduction waiting for the year it becomes profitable. Businesses that simply do not claim in loss years throw that away permanently.

What each group can actually deduct

This is where the regimes genuinely diverge, and it is the single biggest practical difference.

Self-employed may claim a reasonable share of essentially the full cost of occupying the home: heat, electricity, water, home insurance, maintenance and repairs, property taxes, mortgage interest (never principal), and rent if you rent. Capital cost allowance on the business portion of the home is technically available.[5]

Employees - including owner-managers of their own corporation - are on a much shorter list. A salaried employee may generally claim a share of rent and utilities and minor maintenance. A commission employee earning income under paragraph 8(1)(f) may additionally claim a share of home insurance and property taxes. Neither may claim mortgage interest, and neither may claim capital cost allowance.[4]

That gap is the entire reason the incorporation question below matters. An owner who incorporates without thinking about it can quietly lose the mortgage interest and property tax portion of a deduction they had the year before.

Why you should almost certainly not claim CCA on your home

A self-employed person is permitted to claim capital cost allowance on the business-use portion of a home they own. Almost no one should.

Claiming CCA on part of your home is generally treated as changing the character of that portion from personal-use property to business property. When you eventually sell, the principal residence exemption may not shelter that portion of the gain. You will have converted a modest annual deduction into a taxable capital gain on a house that has probably appreciated substantially.

The arithmetic is rarely close. Claim the operating costs. Leave the building alone.

If you are incorporated: two routes

A corporation does not have a home. It cannot deduct your house. So there are exactly two legitimate ways to get home office cost out of a company, and they work very differently.

Route 1: employment expenses via T2200. You are an employee of the corporation, so you deduct work space expenses personally under subsection 8(13), which requires the corporation to sign Form T2200, Declaration of Conditions of Employment.[3] The corporation deducts nothing; you do, against your employment income. You are on the short employee list - no mortgage interest, no CCA - and the conditions of employment must genuinely require you to maintain the work space.

Route 2: the corporation rents the space from you. The company pays you rent for the home office. That rent is a deductible expense to the corporation and rental income to you personally, against which you deduct the corresponding proportional share of your home costs - including mortgage interest and property taxes, because you are now reporting rental income rather than employment income.

Route 2 is more flexible and usually more favourable, but it has to be done properly rather than as a year-end journal entry:

The rent must be reasonable for the space - benchmark it against local commercial or sublet rates, not against your mortgage payment
There should be a written agreement between you and the corporation
The rent should actually be paid, on a schedule, through the bank
You report the rental income and the offsetting expenses on your personal return - it is not tax-free money out of the company
The same principal-residence warning applies: do not claim CCA on the building

Route 2 done casually - no agreement, no payments, a number invented in March - is one of the easier things to unwind on review, and unwinding it leaves a corporate deduction denied and rental income already reported.

Apportioning the space

The deduction is a reasonable share of the whole, and the two accepted bases are square footage and number of rooms. Square footage is more defensible and almost always more accurate; room-count flatters people with one large living room and penalises everyone else.

Where the space is used for both business and personal purposes - a dining room table that is a desk on weekdays - you apportion a second time, by the hours it is used for business over total hours. A room used for business 40 hours out of a 168-hour week is not a full-time business room.

Whichever basis you use, write down the measurements and keep them. The apportionment is the part of a home office claim that actually gets questioned, and "about a third of the house" is not a measurement.

The flat rate method is gone

The temporary flat rate method introduced for the pandemic years let employees claim a per-day amount with no form and no receipts. CRA is explicit that it does not apply to the 2023 and later tax years.[3]

It is still one of the most common assumptions people bring to this topic. If you are an employee claiming a work space today, you are on the detailed method, you need a signed T2200, and you need to be able to support the numbers.

Where this goes wrong

Not claiming in a loss year. The cap defers the deduction; it does not destroy it. Claim, track the carry-forward, use it when you are profitable.

Assuming exclusivity is always required. It is a condition of branch (ii) only. If the space is your principal place of business, branch (i) applies and a reasonable apportionment is enough.

Incorporating and continuing to claim as if self-employed. The moment you are an employee of your own company, you are under 8(13) and the deductible list gets much shorter, unless you set up a proper rental arrangement.

Claiming CCA on the home. A small annual deduction traded for exposure on the principal residence exemption.

Deducting mortgage principal. Only the interest component is ever deductible, and only for the self-employed or under a rental arrangement.

Charging the corporation rent with no agreement and no payments. If it only exists as an adjusting entry, it will not survive.

Still expecting the flat rate method. Gone for 2023 onward.

The bottom line

The home office deduction is one of the few areas where the right answer genuinely changes when you incorporate - and changes for the worse if you do nothing about it. A sole proprietor deducts a share of nearly everything. An employee of their own corporation deducts a much shorter list, unless the corporation rents the space on properly documented terms.

Whichever regime you are in: measure the space, claim it even in loss years, track the carry-forward, and leave capital cost allowance on the building alone.

Frequently asked questions

Does my home office have to be used exclusively for business?

Only under the second branch of the test. Subsections 18(12) and 8(13) allow a deduction where the work space is either your principal place of business (or where you principally perform your employment duties), or is used exclusively for earning income and on a regular and continuous basis for meeting clients or customers. Exclusivity is a condition of the second branch only. If the space is your principal place of business, a reasonable apportionment is sufficient.

Can a home office deduction create a business loss in Canada?

No. Both provisions cap the work space deduction at your income from that business or employment for the year, computed before the deduction. It can reduce income to nil but not below it. However, any amount denied solely because of that cap is deemed deductible in the following year, and because it is subject to the cap again it can chain forward indefinitely. You should still claim in a loss year and track the carry-forward.

What can I deduct if I am incorporated and work from home?

As an employee of your own corporation you fall under subsection 8(13), which is more restrictive than the self-employed rules. You need a signed Form T2200 from the corporation, and you cannot deduct mortgage interest or claim capital cost allowance. The alternative is to have the corporation rent the space from you on a written agreement at a reasonable rate with rent actually paid; you then report rental income and deduct the corresponding share of home costs, including mortgage interest and property taxes.

Can I deduct my mortgage on a home office?

A self-employed person may deduct a reasonable share of mortgage interest, never mortgage principal. An employee, including an owner-manager of their own corporation, may not deduct mortgage interest at all under the employment expense rules. A commission employee may deduct a share of home insurance and property taxes that a salaried employee cannot, but mortgage interest is unavailable to both.

Should I claim capital cost allowance on my home office?

Almost never. Claiming CCA on the business portion of a home you own can jeopardise the principal residence exemption on that portion when you eventually sell, converting a modest annual deduction into a taxable capital gain on an appreciating asset. Claim the operating costs and leave the building out of it.

Can I still use the temporary flat rate method for home office expenses?

No. CRA states that the temporary flat rate method does not apply to the 2023 and later tax years. Employees claiming work space in the home expenses must use the detailed method, obtain a signed Form T2200 from their employer, and be able to support the amounts claimed.

Sources cited in this article

Income Tax Act, subsection 18(12) - Work space in home
The rule for self-employed individuals: the two-branch test, the income cap in 18(12)(b), and the indefinite carry-forward in 18(12)(c).
https://laws-lois.justice.gc.ca/eng/acts/i-3.3/section-18.html
Income Tax Act, subsection 8(13) - Work space in home
The parallel rule for employees, including owner-managers of their own corporation, with its broader 'customers or other persons' wording.
https://laws-lois.justice.gc.ca/eng/acts/i-3.3/section-8.html
CRA - Work space in the home expenses
CRA's guidance for employees, and the confirmation that the temporary flat rate method does not apply to 2023 and later tax years.
https://www.canada.ca/en/revenue-agency/services/tax/individuals/topics/about-your-tax-return/tax-return/completing-a-tax-return/deductions-credits-expenses/line-22900-other-employment-expenses/work-space-home-expenses.html
CRA - T4044, Employment Expenses
The authoritative list of what salaried versus commission employees may deduct for a work space, and the exclusion of mortgage interest and capital cost allowance.
https://www.canada.ca/en/revenue-agency/services/forms-publications/publications/t4044.html
CRA - T4002, Self-employed Business, Professional, Commission, Farming and Fishing Income
Business-use-of-home expenses for unincorporated businesses, including the apportionment basis and eligible costs.
https://www.canada.ca/en/revenue-agency/services/forms-publications/publications/t4002.html
CRA - Form T2200, Declaration of Conditions of Employment
The form an employer, including your own corporation, must sign before you can deduct employment work space expenses.
https://www.canada.ca/en/revenue-agency/services/forms-publications/forms/t2200.html
Income Tax Act, R.S.C. 1985, c. 1 (5th Supp.)
The governing statute. Paragraph 8(1)(f) sets out the commission employee deduction that widens the employee list.
https://laws-lois.justice.gc.ca/eng/acts/i-3.3/

All sources verified 2026-08-12. Spotted a link that has moved? Email support@mapleexpense.com and we will correct it.