Foreign Tax Credit Carryback and Carryforward: Baskets, Limits, Filing

Unused foreign tax credits can be carried back one year and then forward up to ten, giving you an eleven-year window to recover foreign taxes you paid but couldn’t fully use against your U.S. bill. The foreign tax credit carryback and carryforward rules under Section 904(c) are strict about order, income category, and paperwork, and a few common elections can quietly destroy balances you were counting on. Excess credits arise when the taxes you owe another country exceed the IRS ceiling on how much of your U.S. liability those taxes can offset.

Why You End Up With Excess Credits

The credit only offsets the share of your U.S. tax that corresponds to your foreign earnings. The IRS caps it with a formula: foreign-source taxable income divided by total worldwide taxable income, multiplied by your U.S. tax liability.¹

Say you earn $200,000 total, $60,000 of it from foreign sources, and your U.S. liability is $40,000. Your limit is ($60,000 / $200,000) × $40,000 = $12,000. If you actually paid $15,000 to the foreign country, you can claim $12,000 this year. The remaining $3,000 is your unused credit, and it becomes eligible for carryback and carryforward. This mismatch is routine when the foreign rate runs higher than the U.S. rate on the same income.

Credits Stay Locked Inside Their Income Basket

The limitation runs separately for each category of income, often called a basket. You can’t average heavily taxed income in one category against lightly taxed income in another to inflate the credit.² Under Section 904(d), the current baskets are:³

Passive category income, including interest, dividends, royalties, and rents.
General category income, covering most active business earnings and wages.
Foreign branch income attributable to a foreign branch of a U.S. person.
Section 951A (GILTI) category income from controlled foreign corporations.

Excess credits in one basket can only carry back or forward inside that same basket. Passive excess never rescues a general shortfall. Each basket runs its own timeline.

GILTI Credits Don’t Carry at All

Foreign taxes on Section 951A income cannot be carried back or carried forward.² Whatever exceeds the GILTI-basket limit for the year is simply lost. There is no future recovery.

Foreign Branch Credits Carried Back Before 2018

The foreign branch basket was created by the Tax Cuts and Jobs Act for tax years beginning after 2017. If you carry unused foreign branch credits back to a pre-2018 year, they get allocated to the general category basket, since the foreign branch basket didn’t exist then.⁴

The Mandatory Sequence: One Year Back, Then Ten Forward

Section 904(c) requires unused foreign tax to be carried first to the tax year immediately preceding the excess year. Only what the prior year cannot absorb moves forward, and the forward window runs up to ten years after the excess year.⁵ The statute says “shall” and “in that order.” You cannot skip the carryback to save credits for later.

A prior year absorbs excess credits only if it had leftover capacity, meaning its own credit limit was higher than the credits actually used there. If last year’s limit was $8,000 and only $5,000 of credits were claimed, $3,000 of room is available to soak up this year’s excess.

Within the forward window, older credits get used before newer ones. Credits from 2024 apply before credits from 2025 when both are carried into 2026.⁴ That chronological ordering is what keeps the oldest credits from expiring first. Once the ten-year window closes on a batch, those credits are gone permanently. There is no extension, and expired credits cannot be converted to a deduction.

Short Tax Years Burn a Full Slot

A tax year of less than twelve months still counts as one full year toward the carryback or carryforward period.⁴ A short year can quietly consume one of your ten forward slots without offering a full year of income to absorb credits against.

Elections That Block Carryovers

Two common choices can shut carryovers off, and one of them can destroy balances you already have.

Taking the Deduction Instead of the Credit

Each year you choose whether to claim foreign taxes as a credit or as an itemized deduction. You cannot carry credits into or out of a year in which you chose the deduction.⁶ Worse, when carryover credits pass through a deduction year, the IRS treats you as if you had elected the credit that year and computes the limitation anyway. Any capacity in the deduction year absorbs your carryover credits and reduces the balance available to other years, even though you never actually claimed them.⁷ Switching between credit and deduction from year to year can silently erode a large carryover balance.

The $300 De Minimis Election

If your total creditable foreign taxes are $300 or less ($600 or less on a joint return), you can claim the credit directly on your return without filing Form 1116.⁸ The simplification comes with a cost: you cannot carry credits into or out of a de minimis year. Prior-year credits cannot offset tax that year, and any excess that year cannot carry forward. Carryovers between other years still work, but the de minimis year itself is a dead zone.

Currency Conversion Happens Once

Foreign taxes get converted to U.S. dollars in the year they are paid or accrued. Cash-basis taxpayers use the exchange rate on the payment date. Accrual taxpayers generally use the average rate for the tax year the taxes relate to, provided payment happens within 24 months and the currency isn’t inflationary.⁶

Once the credit is stated in dollars, that figure is fixed. Carrying it forward does not mean reconverting at a later year’s rate. The carryover is simply the leftover dollar amount from the year it originated.

Tracking and Reporting the Balance

Individuals report the credit on Form 1116 and track carryover balances on Schedule B (Form 1116), which reconciles prior-year carryover with current-year activity. A separate Schedule B is required for each basket with carryover activity.⁸ Corporations use Form 1118 and Schedule K (Form 1118) for the same reconciliation.⁹

To complete these accurately, keep foreign tax receipts or payment confirmations, copies of foreign returns, exchange rate documentation from each origin year, and records of the capacity available in each carryback or carryforward year. Each credit has to be listed by the year it arose and traced through subsequent years. Errors here are a reliable audit trigger, because the IRS can’t verify your carryover history without them.

How to File a Carryback

Applying excess credits to the prior year requires an amended return. Individuals use Form 1040-X with “Carryback Claim” written at the top of page one, and attach a revised Form 1116, a copy of the original Form 1040 for the credit year marked “Attachment to Form 1040-X—Copy Only—Do Not Process,” any relevant Schedules K-1 or K-3, and any other forms that change as a result, such as Form 6251 for the alternative minimum tax.¹⁰

Form 1040-X can generally be filed electronically for these claims; the IRS does not specifically exclude foreign tax credit carrybacks. Processing usually takes eight to twelve weeks and sometimes stretches to sixteen.¹¹

Carryforwards need no amended return. You attach Schedule B and Form 1116 to your regular annual return, and the prior years’ unused credits offset current-year tax up to the limitation. Save every Schedule B, because each year’s ending balance feeds the next year’s calculation.

When Your Foreign Tax Changes After Filing

Foreign governments issue refunds, adjust liabilities on audit, and accrued taxes sometimes get paid in a different amount than estimated. Each of these is a “foreign tax redetermination,” and it can shift your carryover balances up or down. If the change increases your U.S. tax, you must file an amended return with a revised Form 1116 or 1118 for each affected year, due by the filing deadline (including extensions) for the year the redetermination occurred. Since tax year 2021, Schedule C (Form 1116) reports the redetermination.¹²

Ignoring a redetermination is dangerous. If you don’t notify the IRS, the statute of limitations on that year stays open indefinitely, and additional tax can be assessed at any time.¹² If the change doesn’t raise your U.S. tax because carryover credits absorb it, you report the redetermination on Form 1116 for the year it happened rather than amending earlier years.

You Have Ten Years, Not Three, to Claim a Refund

The normal refund deadline is three years from the filing date, but refunds tied to foreign tax credits get ten years. The clock runs from the due date of the return for the year the foreign taxes were actually paid or accrued.¹³ This is what lets you go back and claim credits you missed or carrybacks you couldn’t see at the time.

AMT and Corporate Ownership Change Notes

If you’re subject to the alternative minimum tax, you calculate a separate AMT foreign tax credit. It follows the same one-year carryback and ten-year carryforward and the same basket separation, but the AMT credit has its own limitation, so the regular and AMT carryover balances move independently.⁷

For corporations, Section 383 restricts how much of a pre-change foreign tax credit carryforward can be used after a significant ownership change. The annual cap parallels the Section 382 rules for net operating losses and is based on the value of the corporation at the change date.¹⁴ Buyers assuming they can freely use a target’s stockpiled credits should price in that limit before closing.

1
Internal Revenue Service. Foreign Tax Credit – How to Figure the Credit
2
Internal Revenue Service. Foreign Tax Credit – Categorization of Income and Taxes Into Proper Basket
3
Office of the Law Revision Counsel. 26 USC 904 – Limitation on Credit
4
eCFR. 26 CFR 1.904-2 – Carryback and Carryover of Unused Foreign Tax
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Office of the Law Revision Counsel. 26 USC 904 – Limitation on Credit – Section: Carryback and Carryover of Excess Tax Paid
6
Internal Revenue Service. Publication 514 – Foreign Tax Credit for Individuals
7
Internal Revenue Service. FTC Carryback and Carryover
8
Internal Revenue Service. Instructions for Form 1116
9
Internal Revenue Service. Schedule K (Form 1118) – Foreign Tax Carryover Reconciliation Schedule
10
Internal Revenue Service. Instructions for Form 1040-X
11
Internal Revenue Service. Where’s My Amended Return
12
Internal Revenue Service. Foreign Tax Redeterminations
13
Office of the Law Revision Counsel. 26 USC 6511 – Limitations on Credit or Refund
14
Justia. 26 US Code 383 – Special Limitations on Certain Excess Credits, Etc.