What Is Form 3800: General Business Credit?

IRS Form 3800, the General Business Credit, is the form businesses use to add up their individual federal tax credits, apply the legal limit on how much of that total can offset this year’s tax, and track any unused amount that carries to another year.¹ It is required whenever you claim any of the credits grouped under Internal Revenue Code Section 38.²

Who Has to File It

Anyone claiming a general business credit files Form 3800 with their income tax return. That covers C corporations attaching it to Form 1120, S corporations, partnerships, estates and trusts attaching it to Form 1041, and individuals with business income, including sole proprietors filing Schedule C.³ You also file it if you have a carryforward from a prior year, even in a year when you earned no new credits.

Partnerships and S corporations usually pass credits through to their partners or shareholders, who then report them on their own Form 3800. Pass-through entities that make elective payment or transfer elections have to complete parts of the form themselves.³ Businesses in a controlled group or under common control are treated as a single employer for certain credit calculations, and the credit is divided proportionately among the members.⁴

Which Credits Feed Into Form 3800

Each individual credit starts on its own form, where you calculate the raw amount based on qualifying wages, spending, or production. You then move those totals onto Form 3800, which adds them and applies the overall cap. Dozens of credits feed in.⁵ Common ones include:

Investment credit on Form 3468, which covers historic rehabilitation, energy property, advanced manufacturing, and clean electricity investments
Work opportunity credit on Form 5884, for hiring workers from targeted groups
Research credit on Form 6765, for qualified research spending
Employer tip credit on Form 8846, reimbursing the employer’s share of Social Security and Medicare taxes paid on tips
Small employer health insurance credit on Form 8941, for businesses paying at least half of employee premiums
Employer credit for paid family and medical leave on Form 8994
Low-income housing credit on Form 8586
Carbon oxide sequestration credit on Form 8933
Disabled access credit on Form 8826, for small-business accessibility improvements
Small employer pension plan startup cost credit on Form 8881

The full list appears in the Form 3800 instructions and on the IRS business tax credits page. A few credits on that page stand alone and are not part of the general business credit, so check the instructions for each credit you claim.⁵

How Much of the Credit You Can Actually Use

The general business credit cannot zero out your entire tax bill. Section 38(c) caps it at the amount by which your net income tax exceeds the greater of two figures: your tentative minimum tax, or 25 percent of your net regular tax liability above $25,000.² A slice of your tax liability is always shielded from being offset.

The pieces of the formula:

Net income tax is your regular tax plus any alternative minimum tax, minus certain personal credits
Tentative minimum tax is the AMT calculated before comparing it to your regular tax
Net regular tax liability is your regular tax minus certain personal credits

Your allowable credit equals net income tax minus whichever is larger: the tentative minimum tax, or 25 percent of net regular tax over $25,000.

Certain “specified credits” get more favorable treatment. When you run the limit for those, the tentative minimum tax is treated as zero, which lets them offset AMT liability that would otherwise block a general business credit.² The research credit, work opportunity credit, employer tip credit, small employer health insurance credit, and employer paid family leave credit are among them.

Eligible small businesses get a further break: their research credit and certain other credits can offset both regular tax and AMT without the usual limit. The business must be a non-publicly-traded corporation, partnership, or sole proprietorship with average annual gross receipts of $50 million or less over the prior three tax years.⁶ For partners and S corporation shareholders, both the entity and the owner have to meet the gross receipts test independently.

What Happens to Unused Credits

If your credits exceed the annual limit, the excess does not vanish. The general rule is a one-year carryback and a 20-year carryforward.⁷ The unused amount goes to the earliest available year first, and whatever remains moves forward.

Two categories run on different clocks:

The marginal oil and gas well production credit has a five-year carryback and a 24-year carryforward
Applicable credits under the elective payment rules of Section 6417 have a three-year carryback and a 22-year carryforward

These are tracked separately from your other general business credits.⁷

Within a year, credits are used first-in, first-out. Carryforwards from the oldest years apply first, then current-year credits, then carrybacks from a later year.³ The order matters because credits applied first get consumed, and credits later in the sequence are the ones most likely to roll forward.

Passive Activity Credits

Credits earned from a business in which you do not materially participate are passive activity credits, and they can generally only offset tax on passive income. They will not reduce tax on wages, active business income, or portfolio income.⁶ Before you put them on Form 3800, individuals run them through Form 8582-CR and corporations through Form 8810.⁸ Form 3800 keeps passive and non-passive credits in separate columns in Part III, and the allowed passive amount flows back into Parts I and II.

How the Form Is Laid Out

Before starting, pull together every individual credit form you have completed, any Schedule K-1 showing credits passed through from a partnership or S corporation, and your records of prior-year carryforwards.

Part I gathers non-passive and passive credits that cannot offset the tentative minimum tax. Part II is where you actually apply the limitation formula: you enter your regular tax and tentative minimum tax, work through the cap, and land on the total credit allowed against your tax on line 38. Any credits above that number become a carryback or carryforward.³

Part III is the itemized breakdown, listing each individual credit and splitting current-year amounts from carryforwards and carrybacks, and passive from non-passive. Part IV handles prior-year carryforwards. Part V is for partnerships and S corporations making elective payment or transfer elections.

Filing and Getting a Carryback Refund

Attach Form 3800 to your annual income tax return, whether that is Form 1120, Form 1040, or the return that fits your entity. Electronic filing is standard for most business returns.¹

To carry an unused credit back to the prior year, corporations can file Form 1139 for a tentative refund or file an amended Form 1120-X.⁹ Individuals, estates, and trusts use Form 1045 for the tentative refund route.¹⁰ An application for a tentative carryback refund has to be filed within 12 months after the end of the tax year the unused credit came from.⁷

Records and Penalties

Keep everything that supports your credits: invoices, payroll records, certifications, energy audits, and any other proof of qualifying activity. The IRS baseline is three years from the date you filed or two years from the date you paid, whichever is later.¹¹ If you are carrying credits forward, hold the underlying records for the whole carryforward period plus three years, since the IRS can examine the original calculation when the credit is finally used.

Claiming more credit than you are entitled to triggers a penalty of 20 percent of the excessive amount under Section 6676, absent reasonable cause.¹² Overstated credits can also draw accuracy-related penalties or, in serious cases, fraud penalties.

What Changed for the 2026 Tax Year

Several credits that used to run through Form 3800 are gone for 2026 under the One Big Beautiful Bill Act. The new clean vehicle credit under Section 30D, the previously-owned clean vehicle credit under Section 25E, and the qualified commercial clean vehicle credit under Section 45W all terminated for vehicles acquired after September 30, 2025.¹³ A vehicle acquired before that date can still generate a credit on the 2025 return, but no new claims are available for 2026.

The clean fuel production credit under Section 45Z stays available through the end of 2029, with changes for fuel produced after December 31, 2025. The applicable credit is now $0.20 or $1.00 per gallon, and the fuel must come exclusively from feedstock produced or grown in the United States, Mexico, or Canada.¹⁴ Sustainable aviation fuel is now subject to the same credit amounts as other transportation fuels, and fuels produced from another transportation fuel no longer qualify. Facilities receiving material assistance from a prohibited foreign entity may be ineligible for certain energy credits.

1
Internal Revenue Service. About Form 3800, General Business Credit
2
Office of the Law Revision Counsel. 26 U.S. Code 38 – General Business Credit
3
Internal Revenue Service. 2025 Instructions for Form 3800 and Schedule A – General Business Credit
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Office of the Law Revision Counsel. 26 U.S. Code 52 – Special Rules
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Internal Revenue Service. Business Tax Credits
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Internal Revenue Service. Instructions for Form 3800 and Schedule A
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Office of the Law Revision Counsel. 26 U.S. Code 39 – Carryback and Carryforward of Unused Credits
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Internal Revenue Service. Instructions for Form 8582-CR – Passive Activity Credit Limitations
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Internal Revenue Service. Instructions for Form 1139
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Internal Revenue Service. About Form 1045, Application for Tentative Refund
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Internal Revenue Service. How Long Should I Keep Records
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Office of the Law Revision Counsel. 26 U.S. Code 6676 – Erroneous Claim for Refund or Credit
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Internal Revenue Service. FAQs for Modification of Sections 25C, 25D, 25E, 30C, 30D, 45L, 45W, and 179D Under the One Big Beautiful Bill
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Internal Revenue Service. One, Big, Beautiful Bill Provisions