Tax Tip Tuesday: Home Office Deduction — What the IRS Is Actually Looking For

Home office desk with tax documents — MKHS Tax Group blog on home office deduction rules

The home office deduction is one of the most misunderstood — and most scrutinized — deductions on a tax return. I see it come up constantly in client conversations, and the same question surfaces every time: "Is it really worth claiming? Will it trigger an audit?"

The honest answer? Done right, the home office deduction is completely legitimate and worth claiming. Done wrong, it's a red flag that can invite exactly the kind of IRS attention you want to avoid. Let's break down what you need to know before you claim it — and before the IRS comes asking.

What Is the Home Office Deduction?

Under IRC §280A, taxpayers who use part of their home regularly and exclusively for business may deduct a portion of home-related expenses — things like rent, mortgage interest, utilities, insurance, and repairs.

There are two methods to calculate it:

1. Simplified Method

• $5 per square foot of your dedicated home office space

• Maximum deduction: 300 sq. ft. ($1,500 cap)

• Easy to calculate; no depreciation recapture later

  
  

2. Regular Method

• Calculate the percentage of your home used for the office (e.g., 200 sq. ft. ÷ 2,000 sq. ft. home = 10%)

• Apply that percentage to actual home expenses

• More paperwork, potentially higher deduction, and depreciation recapture when you sell

  
  

The Two Big Rules the IRS Cares About Most

Rule #1: Regular and Exclusive Use

This is where most people trip up. Your home office space must be used only for business — not occasionally, not "mostly." The IRS doesn't require a separate room, but the space must be clearly dedicated to business. The guest bed in the corner of your "office" is a problem. So is the dining table where you also eat dinner.

Rule #2: Principal Place of Business

You must use your home office as your principal place of business, OR:

• As a place to meet clients/patients regularly, OR

• As a separate free-standing structure (like a detached studio or garage) used for business

If you have a dedicated office elsewhere and occasionally work from home, this deduction likely does not apply to you.

Who Can Actually Claim This?

Self-employed individuals and business owners: Yes — claim it on Schedule C (or Schedule F for farmers). This deduction reduces both income tax and self-employment tax. It matters.

S-Corporation owners/employees: This is more nuanced. If you're an S-corp shareholder-employee, you can't deduct home office expenses on your personal return under current law (the TCJA eliminated the employee business expense deduction through 2025). Instead, the corporation should reimburse you under an accountable plan — and that reimbursement is deductible to the corporation and tax-free to you. If your S-corp isn't doing this, we need to talk.

W-2 employees: Generally not allowed under current law (TCJA 2017–2025). Some states still allow this deduction at the state level — California, for example, still permits it on your CA return under certain conditions.

What Triggers IRS Scrutiny

Let me be direct with you: the home office deduction doesn't automatically invite an audit — but disproportionate deductions relative to your income do. Here's what catches attention:

• Home office expenses that seem too large relative to your reported income

• Claiming the deduction year after year with minimal or no business income

• Using the regular method but claiming nearly 100% of your home

• No clear separation between personal and business space

• Inconsistency between your home office deduction and your reported business activity

The key is documentation. You should be able to show the IRS a floor plan, photos of the dedicated space, and records of how the space is used.

What You Need to Keep on File

If you're claiming the home office deduction, keep these records:

• Floor plan or sketch showing the office square footage vs. total home size

• Photos of the dedicated workspace (timestamped, if possible)

• Receipts for all home expenses you're allocating (rent, mortgage statements, utility bills, insurance)

• Business records showing the office is being used (client meeting logs, appointment calendars, etc.)

• Lease or mortgage documents showing your home address

The IRS has up to 3 years to audit your return from the filing date (longer in cases of fraud or significant underreporting). Keep these records accordingly.

A Quick Note on Depreciation

If you use the regular method and you own your home, you'll depreciate the business-use portion of your home. This lowers your tax bill now — but when you sell, that depreciation must be recaptured and taxed, even if you've otherwise qualified for the §121 home sale exclusion. This is something a lot of taxpayers don't find out about until they're sitting across from me reviewing their sale documents.

Plan ahead. Know the long-term implications before you claim depreciation.

Home Office Deduction Quick Quiz

Let's see how much you've absorbed. Test yourself before you file!

The home office deduction is real, it's legitimate, and for self-employed individuals and business owners, it can generate meaningful tax savings. But it needs to be done correctly — with proper documentation, clear exclusive use, and an understanding of the long-term implications like depreciation recapture.

If you're not sure whether your situation qualifies, or if your S-Corp isn't set up with a proper accountable plan reimbursement, let's connect before next filing season.

📩 Reach out to our team at info@mkhstaxgroup.com