AICPA Representative Tasks (verbatim). 1. Application: Calculate the potential tax savings from utilization of net operating and capital loss carryovers. 2. Application: Identify opportunities to optimize state and local income tax rules in tax planning for business expansion given a specific scenario, including apportionment of income and location of business. 3. Application: Calculate the effect of changing tax rates and legislation on the timing of income and expense items for tax planning purposes given a specific scenario. 4.
C corporations generate net operating losses when deductible expenses exceed gross income. Post-2017 NOLs carry forward indefinitely but may offset only 80% of taxable income in the carryforward year.
KEY: The 80% limitation means a corporation with a large NOL carryforward will always pay some tax in profitable years. The remaining 20% of taxable income is fully taxed at 21%.
Common mistakes
- Applying the 80% NOL limitation to pre-2018 losses. Pre-2018 NOLs offset 100% of taxable income. Trap: "all NOLs are limited to 80%." Correct: only post-2017 NOLs face the 80% cap.
- Deducting corporate capital losses against ordinary income. C corporations cannot offset ordinary income with capital losses. Trap: "use the $200,000 capital loss against operating income." Correct: capital losses offset only capital gains; carry back 3 years or forward 5 years.
- Using the prior-year safe harbor for Q2, Q4 as a large corporation. Large corporations (taxable income ≥$1 million in any of prior three years) may use prior-year safe harbor only for Q1. Trap: "pay last year's tax in four installments." Correct: Q2, Q4 must reflect current-year tax estimates.
Bottom line
- Post-2017 C corporation NOLs carry forward indefinitely but offset only 80% of taxable income per year, with no carryback; pre-2018 NOLs offset 100%.
- Corporate capital losses carry back 3 years and forward 5 years, offsetting only capital gains and never ordinary income.
- State income tax planning exploits apportionment formula differences, single-sales-factor weighting, and throwback/throwout rules to minimize combined state burden.
- When tax rates are expected to rise, accelerate income and defer deductions; reverse the strategy when rates will fall.
Exam shortcut
"80-21-20" for NOLs: Post-2017 NOLs offset 80% of income at 21% rate, leaving 20% of income always taxed. Quick tax on $1M income with unlimited NOL: $1M × 20% × 21% = $42,000. "3 back, 5 forward, gains only" for corporate capital losses: Mnemonic captures the three rules in one phrase. Contrast with individuals: no carryback, unlimited carryforward, $3K ordinary offset.
The full lesson (about 5,276 words, 35 min read) adds 9 worked examples, all 6 common mistakes, a self-check, free in the app.
Learning objectives
- III.B1
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