Updated October 18, 2026. Quick answer: Part IV asks for the facts about your vehicle: when you placed it in service, how many miles were business, commuting and other, whether it was available for personal use, and whether you have written evidence. You complete it only if you claim car or truck expenses on line 9 and are not required to file Form 4562 for the business.
Picking the Schedule C business code for your work (2025 chart): Schedule C code for rideshare and delivery drivers and Schedule C code for truck drivers.
Related reading on this site: IRS Publication 463.
Sales of business property (Form 4797), passive activity losses (Form 8582) and depreciation (Form 4562) for 2025, read line by line: Form 4797 lines 33 to 35 and Form 4562 Part V.
Who completes Part IV
The Part IV heading reads “Complete this part only if you are claiming car or truck expenses on line 9 and are not required to file Form 4562 for this business.” “See the instructions for line 13 to find out if you must file Form 4562.”
The instructions for line 9 explain the split: “If you claim any car and truck expenses, you must provide certain information on the use of your vehicle by completing one of the following.” The first choice is “Complete Schedule C, Part IV, if (a) you are claiming the standard mileage rate, you lease your vehicle, or your vehicle is fully depreciated; and (b) you are not required to file Form 4562 for any other reason.” The second is “Complete Form 4562, Part V, if you are claiming depreciation on your vehicle or you are required to file Form 4562 for any other reason (see Line 13, later).” The deduction itself is on line 9, covered at Schedule C lines 8 and 9. The Form 4562 side is on the Form 4562 page.
Lines 43 to 46: what the form asks
Line 43 is “When did you place your vehicle in service for business purposes?” Line 44 is “Of the total number of miles you drove your vehicle during 2025, enter the number of miles you used your vehicle for:” with three boxes for business, commuting and other. Line 45 asks “Was your vehicle available for personal use during” off-duty hours? Line 46 asks “Do you (or your spouse) have another vehicle available for personal use?” The answers come from your mileage log, your purchase or lease paperwork and your own records.
If you used more than one vehicle, the instructions say “attach a statement with the information requested in Schedule C, Part IV, for each additional vehicle.”
Line 44b: commuting miles
The instructions begin: “In most cases, commuting is travel between your home and a work location.” “If you converted your vehicle during the year from personal to business use (or vice versa), enter your commuting miles only for the period you drove your vehicle for business.”
Some travel is not commuting. Travel “that meets any of the following conditions isn’t commuting; it is considered deductible business travel.” The conditions are:
- “You have at least one regular work location away from your home and the travel is to a temporary work location in the same trade or business, regardless of the distance.” “Generally, a temporary work location is one where your employment is expected to last 1 year or less.”
- “The travel is to a temporary work location outside the metropolitan area where you live and normally work.”
- “Your home is your principal place of business under section 280A(c)(1)(A) (for purposes of deducting expenses for business use of your home) and the travel is to another work location in the same trade or business, regardless of whether that location is regular or temporary and regardless of distance.”
The principal place of business test links to line 30, covered at Schedule C line 30.
Line 47: evidence
Line 47a asks “Do you have evidence to support your deduction?” and 47b asks whether “is the evidence written?” For records the instructions say “Specific recordkeeping rules apply to car or truck expenses.” “For more information about what records you must keep, see Pub. 463.” “You may maintain written evidence by using an electronic storage system that meets certain requirements.”
Where it goes next
Part IV has no dollar total of its own: it holds dates, miles and yes or no answers. The amount you deduct is on line 9, captioned “Car and truck expenses”, and flows into the Part II total at line 28, explained at Schedule C lines 27a to 29. The whole schedule is described on the Schedule C (Form 1040) page, and the return it attaches to is on the Form 1040 page.
Edition and line numbers
This page reads the 2025 Schedule C (Form 1040) and its 2025 instructions, the current files irs.gov served on 2026-10-18. They are byte-identical to the archived copies and they are the files for the tax year 2025 return, filed in 2026. The schedule says “Attach to Form 1040, 1040-SR, 1040-SS, 1040-NR, or 1041”; “partnerships must generally file Form 1065.” Schedule C has its own instructions booklet, titled “Instructions for Schedule C” (Form 1040). Check the tax year printed on the schedule you are filling in and use the line numbers on that year’s schedule, because a different year’s schedule can number or word its lines differently.
Common mistakes
- Completing Part IV when Form 4562 is required. The form says to complete it “only if you are claiming car or truck expenses on line 9 and are not required to file Form 4562 for this business.”
- Leaving out a second vehicle. The instructions say “attach a statement with the information requested in Schedule C, Part IV, for each additional vehicle.”
- Counting temporary work site trips as commuting. The instructions say travel to a work location that fits the listed conditions “isn’t commuting; it is considered deductible business travel.”
Related: Schedule C (Form 1040), Form 4562, and Form 1040.
Sources
- Instructions for Schedule C (Form 1040), Profit or Loss From Business (2025): https://www.irs.gov/pub/irs-pdf/i1040sc.pdf
- Schedule C (Form 1040), Profit or Loss From Business (2025): https://www.irs.gov/pub/irs-pdf/f1040sc.pdf
Read from the IRS documents linked above on October 18, 2026. General information, not tax advice. Your own facts decide the outcome, and a preparer, the account provider or the IRS is the right place to confirm anything consequential.