An HVAC repair in a building you own belongs on Line 21, repairs and maintenance.
Why line 21
Fixing the heating or cooling in a building you own and use for the business is repairs and maintenance on line 21 when the work keeps the system running rather than replacing it. A building is not one asset for this test: the regulations split it into the structure plus nine building systems, and HVAC is one of them, so the question is whether the work bettered or restored the HVAC system itself. Replacing a compressor or a fan motor on a multi unit system is normally a repair, while swapping out the whole system is a restoration that has to be capitalised. A repair to a building you live in is different again: work that benefits the whole house reaches the return only at your business use percentage through line 30, and a full line 21 deduction is available only when the work serves the business space alone.
Stop looking up lines one at a time. ClaryBook totals your year into an IRS Schedule C worksheet in form order, Part I and Part II line by line, so an HVAC repair in a building you own lands on Line 21 without you sorting it.
Start for freeWhat an HVAC repair in a building you own is confused with
- Form 4562, form 4562, carried to schedule c line 13
- Repairing part of the system is line 21, but replacing the whole HVAC system restores a building system and is recovered on Form 4562.
- Line 30, line 30, business use of your home
- If the building is your home, HVAC work benefits the whole house and reaches the return through the home office percentage on line 30 rather than line 21.
- Line 25, utilities
- Line 25 is the gas and electricity bill for running the system, while line 21 is the cost of keeping the equipment working.
Examples that belong on line 21
- A $780 condenser fan motor replacement on a shop rooftop unit
- A $340 service call to recharge refrigerant and fix a leak
- A $1,150 heat exchanger repair on a workshop furnace
- A $220 thermostat and control board repair in a studio you own
- A $460 duct repair after a leak in a retail unit
What does not belong here
- A full HVAC system replacement, which is a restoration and is capitalised.
- HVAC work on a home where only part of the house is a home office, which flows through line 30.
- The utility bill for running the system, which is line 25.
- A new unit installed as part of a capitalised build out.
The limit that applies
Small taxpayer safe harbour for buildings: a business with average annual gross receipts of $10 million or less can elect to deduct amounts paid for repairs, maintenance and improvements on a building with an unadjusted basis of $1 million or less, capped at the lesser of $10,000 or 2 percent of that basis for the year, the figures in force for tax year 2026.
What to keep
Keep the contractor's invoice describing which component was repaired and which system it belongs to, plus the building's repair history. A description that names a part rather than a system is the difference between line 21 and a capitalised asset.
Other expenses on line 21
| Expense | Line |
|---|---|
| a camera sensor clean | Schedule C, Line 21 |
| a laptop screen or battery replacement | Schedule C, Line 21 |
| an annual machinery service contract | Schedule C, Line 21 |
| painting a rented studio | Schedule C, Line 21 |
| pest control | Schedule C, Line 21 |
| repairing a broken tool | Schedule C, Line 21 |
| routine cleaning of business premises | Schedule C, Line 21 |
| servicing business equipment | Schedule C, Line 21 |
Related lookups
- Where does a website build go on Schedule C?
- Can I deduct homeowners insurance for an office?
- Where does internet go on Schedule C?
Sources
This page explains how Schedule C lines work. It is general information, not tax advice for your situation. If an expense is large or the answer turns on a fact about your business, confirm it with your tax preparer.
Looking for a different expense? The full Schedule C line lookup has every line from 8 to 27 with the expenses that belong on each, and Schedule C expense categories walks the whole form in order.
Stop looking up lines one at a time. ClaryBook totals your year into an IRS Schedule C worksheet in form order, Part I and Part II line by line, so an HVAC repair in a building you own lands on Line 21 without you sorting it.
Start for free