What this line means
The amount of operating expenses (utilities, insurance, repairs, rent) from this year or prior years that exceeded your tentative profit limit and are carried forward to next year. These are not lost deductions — they are parked here until you have enough business profit to absorb them. Next year, you enter this carryover amount on the following year’s Form 8829, and the form gives these expenses priority before calculating new deductions.
Does this apply to you?
- You had home office operating expenses that exceeded your tentative profit on line 8
- You carried forward unused operating expenses from a prior year that still have not been absorbed
- You are in the early stages of a business with low revenue and high home expenses
Easy to overlook
Carryovers have no expiration date Unlike some tax benefits that expire after a set number of years, home office expense carryovers survive indefinitely as long as you continue using the home for business. A filer who builds a carryover balance during three lean startup years can deduct it all in year four when revenue increases. The carryover does not expire — but it disappears if you stop using the home for business. 1 IRS Form 8829 instructions — Line 43
Operating expense carryovers are separate from depreciation carryovers Form 8829 tracks two types of carryovers: operating expenses on line 43 and excess casualty losses plus depreciation on line 44. They are deducted in a specific order. Operating expenses from line 43 are absorbed first (after mortgage interest and taxes), and depreciation carryovers from line 44 are absorbed last. Mixing them up changes how much you can deduct in a given year. 2 IRS Publication 587 — carryover of unallowed expenses
Watch out for this
Forgetting to enter prior-year carryovers on this year’s Form 8829. The form does not auto-populate from last year. You must look at last year’s Form 8829, find the carryover amounts on lines 43 and 44, and enter them on this year’s form in the appropriate carryover input lines. If you skip this step, you forfeit deductions you already earned.
Footnotes
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IRS Form 8829 Instructions, Line 43. https://www.irs.gov/instructions/i8829 ↩
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IRS Publication 587, Business Use of Your Home, Carryover of Unallowed Expenses. https://www.irs.gov/pub/irs-pdf/p587.pdf ↩