Home Office Expenses: Distinguish Employee and Self-Employed Rules
The rules differ for employees and the self-employed: measure the space and time devoted to work.
Published 2026-07-21
Two desks in the same house can produce very different tax rights, status deciding everything. The salaried teleworker goes through the conditions set for employees — the employer's form attesting the requirement in support — and deducts a narrow list: a fraction of rent, utilities and maintenance, never the mortgage or property taxes, under the method in force. The self-employed worker deducts more broadly: their share of taxes, insurance, electricity, maintenance and mortgage interest, up to the professional-use proportion. The proportion is calculated by a consistent method — office area over total area, weighted by time for mixed-use spaces — applied the same way year after year, improvisation attracting questions. Documents support it all: signed forms, bills, a floor plan with measurements, an annual folder. This article separates the two regimes line by line and builds the defensible proportion calculation.
Establish the status first, which changes everything
An employee and a self-employed worker do not deduct the same expenses, and that status is determined by the working relationship's real nature rather than by the contract's label. An employee deducts a restricted list, only where the employer certifies the conditions of employment require it, while a self-employed worker deducts expenses incurred to earn business income, a considerably broader list. A worker invoicing by contract without genuinely being self-employed risks reclassification, with the deductions recovered. That status gets clarified before building anything on top of it.
Measure the space and the time of use
The deduction rests on a proportion, and that proportion is calculated on a reasonable and consistent basis. The usual method uses the work space's area divided by the home's total area. A space shared with personal use requires a further adjustment for time of business use: a dining table used twenty hours a week is not deducted like a closed office. The underlying condition requires the space to be the principal place of work, or to be used exclusively for work and for meeting clients regularly.
Allocate expenses using a consistent method
Eligible expenses differ by status. An employee can generally deduct a share of rent, electricity, heating and certain supplies, but not mortgage interest, municipal taxes or home insurance. A self-employed worker can include those latter items on the same proportion. The allocation method chosen must stay the same year to year, and a change is justified by a real change in circumstances. A limit applies in both cases: the deduction cannot create a loss, the excess carrying forward to later years.
Keep the required forms and records
An employee needs the form signed by their employer certifying the conditions of employment, without which the deduction is denied; that document is requested early in the year rather than in April. Invoices, leases, utility statements and the area calculation are kept, the administration being able to ask for them years later. One consequence is worth knowing before deducting: deducting ownership-related expenses can affect the principal residence status of part of the home on a future sale, a consideration to weigh when settling on the method. A brief written note explaining the method chosen, filed with the receipts, also answers the question years later when nobody remembers why the proportion was set where it was. Two sentences are enough, provided they are written while the reasoning is still fresh.
Quebec scenario: compare before confirming
In the same Saint-Hyacinthe bungalow, two desks face each other: that of a human-resources advisor, salaried and working from home three days a week, and that of her spouse, a self-employed graphic designer. At tax time they assume the same room grants the same rights; their accountant dismantles the symmetry in ten minutes, because status decides everything. For her, the employee, the frame is narrow: the deduction runs through the conditions set for salaried workers, the employer's form attesting that telework is required, and the eligible expenses are essentially limited to a fraction of rent, utilities and maintenance — never the mortgage or property taxes — under the detailed method in force that year. For him, self-employed, the perimeter widens: his share of taxes, insurance, electricity, maintenance and mortgage interest becomes deductible, up to the professional-use proportion. The allocation method, next, gets chosen and kept: each office measured against the home's total area, 11% for her, 14% for him, proportions applied consistently year after year — annual improvisation being what attracts questions. The paperwork last: signed forms, utility bills, a floor plan with measurements, filed in a shared folder. Both deductions hold up precisely because they do not resemble each other: same address, same shared wall, two tax regimes — and now two files that know it.
Checklist
- Establish the status, employee or self-employed
- Obtain the employer's signed form
- List the eligible expenses by status
- Measure the office's and home's areas
- Weight by time for mixed-use spaces
- Apply the same method every year
- Keep the bills and measured floor plan
- Build one annual folder per person
- Revise the calculation if the use changes
Frequently asked questions
Why don't my spouse and I have the same rights for the same office?
Because status decides everything: the employee goes through the conditions set for salaried workers, employer's form in hand, and deducts a narrow list; the self-employed person deducts their share of taxes, insurance, electricity, maintenance and mortgage interest, up to the professional-use proportion.
How is the professional-use proportion calculated?
Through a consistent method — generally the office's area over the home's total area — applied the same way year after year: annual improvisation attracts questions. A mixed-use space is also weighted by professional usage time, under the applicable rules.
Which documents support the deduction?
The employer's signed form for the employee, utility and maintenance bills, the floor plan with measurements, and the proportion calculation — all in an annual folder. The deduction is defended by its documents; without them, it gets negotiated.