The home office deduction is the most-feared, most-misunderstood line on Schedule C. Most solo operators either skip it entirely (leaving $2K-$8K on the table) or take the easy-button simplified version (leaving the bigger half on the table). Here's how to pick.
IRC §280A says: you generally can't deduct anything for the home where you live. Exception: if part of the home is used regularly and exclusively as your principal place of business, you can deduct the business-use percentage of mortgage interest, property tax, utilities, insurance, repairs, depreciation, HOA, even a portion of internet and security.
Two methods to claim it:
1. Simplified. $5 per square foot. Cap of 300 sq ft. Maximum deduction $1,500. No Form 8829 required. No depreciation recapture later. Schedule C Line 30 only.
2. Actual. Compute the business-use percentage (office sq ft ÷ total home sq ft), apply it to every home expense, depreciate the business-use portion of the home over 39 years. Reported on Form 8829. No cap — wins for almost everyone with a real home office > 150 sq ft.
One catch: the deduction can't drive the business into a tax loss (§280A(c)(5)). Anything you can't use carries forward to next year. And under the actual method, depreciation taken on the home portion is recaptured at sale.
Same office. Same year. Method choice doubles the deduction.
Net pickup: Priya's actual-method deduction beats simplified by $1,747. After federal income tax (32%) + self-employment tax (15.3% on the SE-tax-relevant portion) + PA local (3.07%), the actual method is worth roughly $1,000 more in cash per year. Over 10 years: ~$10K. The "easy button" simplified method is the wrong button for her.
You can switch between methods year-to-year. There's no "lock-in." Pick simplified one year, actual the next, simplified again. Only depreciation has continuity — once you take it under the actual method, the basis adjustment sticks.
The room (or clearly demarcated portion of a room) must be used only for business, on a regular basis. A guest bed in the office is a problem. A spouse's craft table in the corner is a problem. A separate desk + dedicated chair + business-only computer is fine.
Either: the home office is where you generate revenue, or it's where you handle the admin/management of the business and you have no other fixed location where you substantially do that work. (Commissioner v. Soliman backed this up; Treas. Reg. §1.280A-2 codifies it.) A field-service plumber who quotes, schedules, books, and bills from a home office qualifies even though the actual work happens at customers' houses.
Take a tape measure to the office and the whole home. Photograph the office. Save a floor plan. Audit defense in three minutes.
Mortgage interest, property tax, homeowners insurance, all utilities, security system, HOA, repairs to the whole home. Don't forget depreciation on the home itself (39-year straight-line on the business-use portion of basis).
Indirect (whole-home) expenses × business-use %. Direct expenses (e.g., painting only the office) = 100% deductible. Repairs to other rooms = 0% to the office.
Form 8829 computes the limit (can't exceed net Schedule C income before this deduction). Excess carries forward indefinitely on Form 8829 Line 43 for next year.
S-corp owners can't take §280A directly on Schedule C — they're employees of their own corp. Set up a written accountable plan, submit an expense report monthly with the home-office %-allocation, and reimburse yourself. The reimbursement is deductible to the S-corp and tax-free to the shareholder. Same dollars, different mechanic.
If the only bedroom is also the office, the exclusive-use test is hard to win. Examiners ask: "Where do you sleep?" Have a real answer.
An office bigger than ~25% of the home raises proportionality questions. Be ready with photos and a floor plan.
Utility bills out of line with the home size or local averages — IRS flags it. Keep the bills.
If §280A(c)(5) limits the deduction to zero but you took it anyway, that's an automatic correction notice.
TCJA (2017) eliminated the home office deduction for W-2 employees through 2025. If you're a W-2, you can't take it on Schedule A as a miscellaneous itemized deduction. (Only Schedule C / self-employed.)
Actual-method depreciation recapture is computed on Form 4797 at sale. Unrecaptured §1250 gain taxed up to 25%. IRS gets the 1099-S — they know.
Drop in your home expenses + office sq ft + total home sq ft. Books calculates both methods, picks the winner, and prepares the Form 8829 worksheet — cited to Pub 587 and §280A.
Figures reflect 2025 IRS rules including Rev. Proc. 2013-13. This is education, not advice. Recapture rules at sale can shift the cost-benefit calculus — model it before you sell.