Key Takeaways

  • GBC is aggregation of dozens of credits reported on Form 3800.
  • Credits reduce tax dollar-for-dollar (unlike deductions).
  • GBC limited to net income tax minus greater of TMT or 25% of tax exceeding $25,000.
  • Unused GBC: carryback 1 year, carryforward 20 years (FIFO).
  • MFS: $25,000 threshold splits to $12,500 each.
  • Common credits: WOTC, R&D, Investment, Disabled Access.
Last updated: January 2026

General Business Credit Overview

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 May 2025 - February 2026 testing window, you are tested on credit rules as of December 31, 2024 (Tax Year 2024).

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.

FormPurpose
Form 3800Aggregates all GBC credits
Individual credit formsCalculate each specific credit
Schedule 3Report total on Form 1040

Credits vs. Deductions

FeatureCreditDeduction
ReducesTax liabilityTaxable income
ValueDollar-for-dollarDepends on tax bracket
Example$1,000 credit = $1,000 saved$1,000 deduction @ 37% = $370 saved

Common Credits in the GBC

CreditFormPurpose
WOTCForm 5884Hiring targeted groups
R&D CreditForm 6765Research activities
Disabled AccessForm 8826Accessibility improvements
Investment CreditForm 3468Energy/rehabilitation property
Low-Income HousingForm 8586Affordable housing

The GBC Limitation Formula

The GBC is non-refundable and limited:

ElementFormula
Net Income TaxRegular tax + AMT - nonrefundable credits
Minus greater of:
Test 1Tentative Minimum Tax (TMT)
Test 225% of (Net Regular Tax - $25,000)

Limitation Example

ItemAmount
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

RuleDescription
First $25,000100% offset by credits
Excess over $25,00075% offset (25% reserved)

Married Filing Separately

Filing StatusThreshold
MFJ/Single/HOH$25,000
MFS (both have credits)$12,500 each
MFS (one has no credits)Full $25,000

Carryback and Carryforward

RulePeriod
Carryback1 year
Carryforward20 years
OrderFIFO (oldest credits first)

Credit Ordering

PriorityCredits
1Carryforwards (oldest first)
2Current year credits
3Carrybacks applied to prior year

Real-World Scenario

Scenario: Tech startup has $50,000 tax liability 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:

  1. Form Questions: "What form aggregates business credits?"
  2. Carryover Questions: "What is the carryback/carryforward period?"
  3. Limitation Questions: "What is the 25% rule for excess liability?"

The key is to remember: Form 3800. Carryback 1 year, forward 20 years. 25/25 rule: First $25k = 100%, excess = 75%.

Test Your Knowledge

What form aggregates the General Business Credit?

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Test Your Knowledge

Unused GBC—what is the carryback/carryforward period?

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Test Your Knowledge

GBC limitation for tax over $25,000?

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