01
Scenario
One business, reported on a personal return — and a set of forms that all depend on each other.
The assignment was to prepare a complete 2025 federal individual income tax return from a classroom case. The taxpayer in the case runs a CPA practice as a sole proprietor, so the business is reported on Schedule C as part of the individual return rather than on a separate entity return.
That one fact shapes most of the return. Business profit is subject to both income tax and self-employment tax. Business assets are depreciated on Form 4562. The owner may qualify for the qualified business income (QBI) deduction. And estimated tax payments made during the year are credited against the final tax.
02
Tax issues in the case
Business income and expenses
Classifying the case’s receipts and costs as Schedule C income and deductible business expenses to reach net profit.
Depreciation
Applying Section 179 expensing, bonus depreciation, regular MACRS, and the listed-property rules on Form 4562.
Self-employment tax
Computing Social Security and Medicare tax on net earnings from self-employment on Schedule SE.
Deductible half of SE tax
Carrying the deductible part of self-employment tax to Schedule 1 as an adjustment to income.
QBI deduction
Evaluating the qualified business income deduction for the practice on Form 8995.
Estimated payments
Applying the year’s estimated federal tax payments on Form 1040 to reach a refund or balance due.
03
Forms used
| Form | What it does | Where it goes |
|---|---|---|
| Form 4562 | Depreciation and Section 179 expense for business assets, including listed property | Depreciation expense on Schedule C, Line 13 |
| Schedule C | Profit or loss from the sole-proprietor business | Net profit (Line 31) to Schedule 1 and Schedule SE; basis for QBI on Form 8995 |
| Schedule SE | Self-employment tax on net earnings | SE tax to Schedule 2; deductible half to Schedule 1 |
| Schedule 1 | Additional income and adjustments to income | Business income and the SE tax adjustment into Form 1040 |
| Schedule 2 | Additional taxes | Self-employment tax into total tax on Form 1040 |
| Form 8995 | Qualified business income deduction, simplified computation | QBI deduction on Form 1040 |
| Form 1040 | The individual income tax return | Taxable income, total tax, payments, and the refund or amount owed |
04
How the return flows
Each form needs a number from the one before it. Depreciation has to be known before Schedule C can be finished, and Schedule C’s net profit drives self-employment tax, the QBI deduction, and the income reported on Form 1040.
Source
Depreciation
Business profit
Built on net profit
Carried forward
The return
Result
05
Build order
Because of those dependencies, a return like this has to be built in order. Getting an early form wrong changes every form after it.
Organize the case facts
Sort each item into business income, business expense, depreciable asset, or a personal item that belongs elsewhere on the return.
Compute depreciation on Form 4562
Apply Section 179 first, then bonus depreciation, then MACRS to any remaining basis, and check business-use percentage for listed property.
Complete Schedule C
Report gross receipts and expenses, including depreciation, to arrive at net profit.
Compute self-employment tax on Schedule SE
Work from net profit to net earnings from self-employment and the resulting SE tax.
Carry amounts to Schedules 1 and 2
Business income and the deductible half of SE tax go to Schedule 1; SE tax goes to Schedule 2.
Evaluate the QBI deduction on Form 8995
Start from qualified business income, reduced by the deductible part of SE tax, and apply the taxable-income limit.
Finish Form 1040
Bring together AGI, deductions, taxable income, tax, and other taxes, then apply estimated payments to reach the result.
06
Key concepts
One profit, two taxes
The same Schedule C profit is subject to income tax (through Schedule 1) and to self-employment tax (through Schedule SE and Schedule 2). An error on Schedule C carries into both.
Depreciation has an order
Section 179 expensing comes first, then bonus depreciation on the remaining basis, then regular MACRS. Section 179 is also limited to taxable income from the business.
Listed property needs a business-use test
For listed property such as passenger vehicles, Section 179, bonus depreciation, and accelerated MACRS generally require more than 50% qualified business use. Otherwise the straight-line alternative system applies.
Self-employment tax has its own base
Net earnings from self-employment are 92.35% of Schedule C net profit. The 15.3% rate covers Social Security, up to the annual wage base, and Medicare. Half of the tax is deductible as an adjustment to income.
The QBI deduction sits below AGI
It reduces taxable income, not adjusted gross income. Form 8995 is the simplified computation for taxable income at or below the annual threshold. Above it, Form 8995-A applies, along with limits for specified service businesses such as an accounting practice.
Payments close the loop
Estimated payments made during the year with Form 1040-ES are credited against total tax on Form 1040. The difference is the refund or the balance due.
07
What I developed
- Turning facts into formsReading a written case and placing each item on the right form and line.
- Depreciation decisionsApplying Section 179, bonus, MACRS, and listed-property rules in the right order.
- Self-employment tax and QBIComputing SE tax on Schedule SE and evaluating the QBI deduction on Form 8995.
- Seeing the whole returnTracing how a number on one form moves through the others to the final result.