17.1 General Business Credit Overview
Key Takeaways
- GBC is aggregation of dozens of business credits reported on Form 3800.
- Credits reduce tax dollar-for-dollar (unlike deductions, which reduce taxable income).
- GBC limited to net income tax minus greater of TMT or 25% of net regular tax over $25,000.
- Unused GBC: carryback 1 year, carryforward 20 years (FIFO ordering).
- MFS: $25,000 threshold splits to $12,500 each spouse when both have credits.
- 2025 OBBBA highlights: WOTC extended through 2026; §45S paid leave credit made PERMANENT; §30D, §45W, §179D, §45L energy credits terminated.
Why This Matters for the Exam
The General Business Credit is fundamental to Part 2. The exam tests the limitation formula, carryback/carryforward rules, and the difference between credits and deductions.
Exam Note: For the July 2026 – February 2027 testing window, you are tested on credit rules as of December 31, 2025 (Tax Year 2025), which reflects the One Big Beautiful Bill Act (OBBBA, signed July 4, 2025).
Expect at least 3-4 questions on the GBC.
What Is the General Business Credit?
The GBC is not one credit—it's a collection of business credits aggregated on Form 3800.
| Form | Purpose |
|---|---|
| Form 3800 | Aggregates all GBC credits |
| Individual credit forms | Calculate each specific credit |
| Schedule 3 | Report total on Form 1040 |
Credits vs. Deductions
| Feature | Credit | Deduction |
|---|---|---|
| Reduces | Tax liability | Taxable income |
| Value | Dollar-for-dollar | Depends on tax bracket |
| Example | $1,000 credit = $1,000 saved | $1,000 deduction @ 37% = $370 saved |
Common Credits in the GBC (2025 status)
| Credit | Form | 2025 Status |
|---|---|---|
| WOTC (§51) | Form 5884 | Extended through Dec 31, 2026 by OBBBA |
| R&D Credit (§41) | Form 6765 | Structure unchanged; up to $500K payroll-tax offset for QSBs |
| §45S Paid Family & Medical Leave | Form 8994 | Made PERMANENT by OBBBA |
| Disabled Access (§44) | Form 8826 | Unchanged ($5,000 max) |
| Investment Credit (§46) | Form 3468 | Energy/rehab property |
| Low-Income Housing (§42) | Form 8586 | Unchanged |
| §30D Clean Vehicle Credit | Form 8936 | TERMINATED by OBBBA for vehicles acquired after Sep 30, 2025 |
| §45W Commercial Clean Vehicle | Form 8936-A | TERMINATED by OBBBA after Sep 30, 2025 |
| §179D Energy Efficient Bldg Deduction | — | $5.81/sf for 2025; OBBBA terminates for construction starting after June 30, 2026 |
| §45L New Energy Efficient Home | Form 8908 | OBBBA terminates June 30, 2026 ($2,500 / $5,000) |
The GBC Limitation Formula
The GBC is non-refundable and limited:
| Element | Formula |
|---|---|
| Net Income Tax | Regular tax + AMT - nonrefundable credits |
| Minus greater of: | |
| Test 1 | Tentative Minimum Tax (TMT) |
| Test 2 | 25% of (Net Regular Tax - $25,000) |
Limitation Example (Tax Year 2025)
| Item | Amount |
|---|---|
| Regular tax liability | $100,000 |
| Excess over $25,000 | $75,000 |
| 25% of excess | $18,750 |
| Maximum GBC allowed | $81,250 |
| Tax after GBC | $18,750 |
The 25/25 Rule
| Rule | Description |
|---|---|
| First $25,000 | 100% offset by credits |
| Excess over $25,000 | 75% offset (25% reserved) |
Married Filing Separately
| Filing Status | Threshold |
|---|---|
| MFJ/Single/HOH | $25,000 |
| MFS (both have credits) | $12,500 each |
| MFS (one has no credits) | Full $25,000 |
Carryback and Carryforward
| Rule | Period |
|---|---|
| Carryback | 1 year |
| Carryforward | 20 years |
| Order | FIFO (oldest credits first) |
Credit Ordering
| Priority | Credits |
|---|---|
| 1 | Carryforwards (oldest first) |
| 2 | Current year credits |
| 3 | Carrybacks applied to prior year |
Real-World Scenario
Scenario: Tech startup has $50,000 tax liability in 2025 and $60,000 in R&D credits.
- Limitation: $50,000 - (25% × $25,000) = $43,750 max credit.
- Credits used: $43,750.
- Tax owed: $6,250.
- Unused credits: $16,250 → carryback 1 year, then forward 20 years.
On the Exam
Expect 3-4 questions on GBC, typically:
- Form Questions: "What form aggregates business credits?"
- Carryover Questions: "What is the carryback/carryforward period?"
- Limitation Questions: "What is the 25% rule for excess liability?"
- OBBBA Questions: "Which credit was made permanent by OBBBA?" (§45S) or "Which clean-energy credits did OBBBA terminate?"
The key is to remember: Form 3800. Carryback 1 year, forward 20 years. 25/25 rule: First $25k = 100%, excess = 75%. OBBBA — §45S permanent; WOTC extended through 2026; §30D/§45W/§179D/§45L terminated.
What form aggregates the General Business Credit?
Unused GBC—what is the carryback/carryforward period?
GBC limitation for tax over $25,000?