The home office deduction is one of the most valuable available to self-employed professionals — and one of the most frequently claimed incorrectly. The IRS has specific requirements, and meeting them matters: this is a deduction that gets scrutinized.
The two requirements
To claim a home office deduction, the space must satisfy two tests:
- Regular and exclusive use — The space must be used regularly and exclusively for your business. A desk in a guest bedroom that sometimes hosts overnight visitors doesn't qualify. A dedicated room used only for client work does.
- Principal place of business — The home office must be your principal place of business, or a place where you meet clients or customers in the normal course of business, or a separate structure used in connection with the business.
What "exclusive use" actually means
This is where most home office claims run into trouble. Exclusive use means the space is used only for business — not "mostly" for business. The IRS does not allow prorating mixed-use space as a home office. If your children do homework at your desk or your spouse handles personal email there, the space does not qualify.
The good news is that exclusive use applies to the space, not to the structure. A section of a room can qualify if it is clearly delineated and used only for business — though a physically defined space (a separate room) is much easier to defend.
Calculating the deduction
You can calculate the deduction one of two ways:
- Simplified method — $5 per square foot of home office space, up to 300 square feet. Maximum deduction of $1,500. Simple and requires no depreciation recapture when you sell.
- Regular method — Divide the square footage of the office by the total square footage of the home to calculate a business-use percentage. Apply that percentage to home expenses: mortgage interest, rent, utilities, insurance, and depreciation. Higher potential deduction but requires recordkeeping and triggers depreciation recapture on sale.
If you use the regular method and deduct depreciation, selling your home later will trigger depreciation recapture tax on the portion allocated to the office. This is a real future cost that should factor into your calculation.
W-2 employees: the answer is no
Since the 2017 Tax Cuts and Jobs Act, W-2 employees who work from home — even full-time remote employees — cannot claim the home office deduction on their federal return. This deduction is available only to self-employed individuals and business owners.
Documentation you need
Keep a floor plan or photograph showing the dedicated space. Maintain records of your home's total square footage and the office's square footage. Save all home expense receipts that feed into the regular method calculation. A clean paper trail is the difference between a solid deduction and a disallowed one.
