Home Office Deduction: Complete Guide for Small Business Owners

Home office requirements (must meet BOTH):

1. Exclusive use: the space must be used ONLY for business. A desk in the corner of a bedroom used for both work and personal activities does NOT qualify. A spare bedroom used solely as an office DOES qualify. Exceptions: daycare facilities and storage of inventory or product samples.

2. Regular use: the space must be used for business on a regular basis (not occasionally). There is no specific hour requirement, but daily or near-daily use is the standard.

Two calculation methods:

Simplified method:

• $5 per square foot of the home office
• Maximum: 300 square feet ($1,500)
• No depreciation on the home (avoids depreciation recapture at sale)
• Cannot carry over unused deduction to future years
• Simplest: one number, no tracking of housing costs

Actual method:

• Calculate the percentage of home used for business (office square footage / total home square footage)
• Apply that percentage to:
  • Mortgage interest or rent
  • Property taxes
  • Utilities (electric, gas, water, internet)
  • Homeowner’s or renter’s insurance
  • Repairs and maintenance (general home repairs prorated; office-specific repairs at 100%)
  • Depreciation (for homeowners: the business portion of the home’s value, depreciated over 39 years)
• Direct expenses (painting only the office, for example) are 100% deductible
• Indirect expenses (whole-house utilities, insurance) are prorated by the business percentage

The commuting mileage conversion (the hidden benefit):

• Without a home office: driving from home to a regular work location is commuting (NOT deductible)
• With a qualifying home office as the principal place of business: driving from home to ANY business location is deductible business mileage
• This reclassification can be worth far more than the home office deduction itself

S-Corp owner rules:

• S-Corp owner-employees cannot deduct the home office on their personal return (TCJA eliminated unreimbursed employee expenses)
• Solution: the S-Corp adopts an accountable plan and reimburses the owner for the home office expense
• The reimbursement is tax-free to the owner and deductible by the S-Corp
• Same calculation (simplified or actual), but run through the accountable plan
• An S-Corp can also rent the space from the owner (the owner reports rental income, the S-Corp deducts rent). This is more complex and has additional rules.

Depreciation recapture warning (actual method, homeowners only):

• If you use the actual method and depreciate a portion of your home, when you sell the home you must recapture the depreciation (taxed at 25%)
• This does NOT affect the IRC 121 exclusion ($250,000 single / $500,000 MFJ) on the non-business portion of the gain
• The depreciation recapture is only on the business-use portion
• If you claim the simplified method: no depreciation, no recapture risk