Even though your actual work happens on job sites, you can still take the home office deduction. The IRS allows it as long as you have a dedicated space in your home that you use regularly and exclusively for business. For most contractors, that means the room or area where you handle estimates, scheduling, invoicing, bookkeeping, and other admin work.

The key requirement is “regular and exclusive use.” The spare bedroom where you do your paperwork qualifies. The kitchen table where you sometimes spread out plans does not. The space doesn’t need to be a full room, but whatever area you claim can’t double as personal space. A desk in the corner of a room that’s otherwise used as a guest bedroom creates problems.

There are two ways to calculate the deduction. The simplified method gives you $5 per square foot of dedicated office space, up to 300 square feet. That’s a maximum of $1,500. It’s easy to calculate and requires less recordkeeping, but it also caps your deduction at a relatively low number.

The regular method lets you deduct the actual expenses of maintaining your home, proportional to the percentage your office takes up. If your office is 200 square feet and your home is 2,000 square feet, you can deduct 10% of qualifying expenses. Those include rent or mortgage interest, property taxes, homeowner’s insurance, utilities, internet, and general home repairs. You can also deduct 100% of improvements made directly to the office space itself, like adding built-in shelving or better lighting.

For contractors running a business with significant revenue, the regular method almost always produces a larger deduction. But it requires you to track those household expenses throughout the year and keep documentation. This is one of many reasons having accurate books matters. Without organized records, contractors either skip this deduction entirely or guess at the numbers and hope for the best.

If you own your home, the regular method also allows depreciation on the portion of the home used for business. This is a real tax benefit but it does have implications when you sell the home, so it’s worth discussing with someone who handles tax strategy before you claim it.

One thing contractors sometimes overlook is that the home office also establishes a tax-deductible starting point for business mileage. When you drive from your home office to a job site, that trip counts as a business trip. Without a qualifying home office, commuting from home to your first job site may not be deductible. For contractors driving across Long Beach or Greater LA every day, that mileage adds up fast.

The home office deduction is one of many write-offs that contractors leave on the table simply because they don’t have the records to support it. If you’re running your business from home and not claiming this deduction, or if you’re unsure whether you’re calculating it correctly, contractor bookkeeping services that keep your expenses organized throughout the year make it much easier to capture every dollar you’re entitled to at tax time.