Foreign Tax Credit Carryover: Using Excess Credits (Schedule B)

Expats and cross-border investors in high-tax countries run into the same surprise every filing season: their Form 1116 shows a foreign tax credit limitation lower than the foreign tax they actually paid. The natural conclusion, that the difference is simply gone, is wrong. A foreign tax credit carryover lets that excess reduce U.S. tax in a different year, but only if you carry it back and forward correctly, keep it inside the right income category, and track it on the schedule the IRS built specifically for this problem.

What Is the Foreign Tax Credit Carryover, and Why Does It Happen?

It happens when the foreign tax you paid on a category of income exceeds the Section 904 limitation computed for that category in that year, and it is common wherever a country's income tax rate runs higher than the U.S. rate on the same income. The foreign tax credit under Form 1116 is capped by a formula: U.S. tax before credits, multiplied by foreign source taxable income in the category divided by total taxable income. That ratio measures how much of your total U.S. tax is attributable to the foreign income, and it is the most you can credit against that income in the current year, no matter how much foreign tax you actually paid.

In a country whose marginal income tax rate on wages or investment income runs above the taxpayer's own U.S. marginal rate on that same income, the foreign tax paid will routinely exceed the limitation. The gap between what you paid and what the formula allows this year is the excess credit. IRC Section 904(c) is what keeps that excess from simply disappearing.

How Does the One Year Carryback and Ten Year Carryforward Work?

Excess foreign tax credit first carries back to the immediately preceding tax year, and only the amount not absorbed there moves forward. IRC Section 904(c) makes the one year carryback mandatory, not an election you can skip in favor of carrying everything forward. If the prior year's own Section 904 limitation for that category has room left after its own current year foreign tax, the carryback fills that room first.

Whatever remains after the carryback carries forward in order, one year at a time, through each of the next ten tax years. The current year's own foreign taxes are credited against that year's Section 904 limitation first; only leftover limitation room then absorbs carryovers, and among carryovers the oldest year is used before newer ones (FIFO), so the excess generated this year sits at the back of the line. Anything still unused after the tenth carryforward year expires permanently.

Using the carryback in practice usually means filing an amended return for the prior year, attaching a recomputed Form 1116 and Schedule B for the category involved. That is more workable than it sounds, because IRC Section 6511(d)(3)(A) grants a special ten year statute of limitations for a refund claim attributable to a foreign tax credit, measured from the due date of the return for the year the excess arose, well beyond the general three year refund window.

Why Can't You Use a Carryover From One Category to Offset Another?

Because IRC Section 904(d) requires the limitation itself, and therefore any carryover it produces, to be computed separately for each separate limitation category. A carryover generated in the passive category can only reduce U.S. tax on passive category income in a later year; it cannot touch a shortfall in the general category, even in the very same return.

The categories that matter for most individual taxpayers are general category income, passive category income (most interest, dividends, and rents), foreign branch category income, income re-sourced by treaty under Section 904(d)(6), and the category for GILTI inclusions under Section 951A, now labeled net CFC tested income. Congress built the separate baskets specifically to stop a taxpayer from blending a high-tax category with a low-tax one to average the rates and manufacture more usable credit than either category earns on its own.

The GILTI or net CFC tested income category is the sharp exception to the carryover rule itself. Excess foreign tax credit in that category gets no carryback and no carryforward at all under Section 904(c): whatever is not usable in the current year is simply gone, which makes real-time planning for that category far less forgiving than for general or passive category income.

What Does Form 1116 Schedule B Actually Do?

Schedule B, the Foreign Tax Carryover Reconciliation Schedule, is where you reconcile the running carryover balance for a category from one year to the next: the beginning balance carried in from prior years, any addition from the current year's excess or a carryback, how much of the balance was actually used against the current year's limitation, and the ending balance carried into the future. The IRS added Schedule B starting with the 2021 Form 1116, replacing the informal carryover tracking many preparers had kept on their own worksheets before that.

You need a separate Schedule B for every category in which you are generating a new carryover or drawing down an existing one, and its instructions call for attaching it whenever that reconciliation applies, not only in the year you finally have enough limitation room to use an old balance. Skipping it in a generating year is the mistake that costs taxpayers later: without a contemporaneous Schedule B, substantiating a carryover from six years ago, in the exact year the IRS asks for it, becomes a documentation problem instead of a form you already filed.

What Is High Tax Kickout, and How Does It Change Which Basket Income Falls Into?

High tax kickout moves an item of passive income, and the foreign tax paid on it, out of the passive category and into the general category when the foreign tax rate on that item exceeds the highest U.S. tax rate that would otherwise apply to it. The mechanism sits in Treas. Reg. Section 1.904-4(c), and it applies item by item rather than to an entire account or an entire year of passive income at once.

The effect on a carryover can run either direction. Recharacterizing high-taxed interest or dividends into the general category can create room to absorb an existing general category carryover that had nowhere to go, or it can push a new excess into the general category instead of the passive one, changing which basket's ten year clock that excess is now running on. Anyone holding a large passive category carryover should check whether kickout affected the composition of that basket before assuming this year's passive income will be the thing that finally uses it.

Does Choosing the FEIE Forfeit Your Foreign Tax Credit Carryover?

Yes, for whatever portion of foreign tax is tied to the income you actually excluded. IRC Section 911(d)(6) denies any credit or deduction for foreign tax paid or accrued on amounts excluded under the foreign earned income exclusion. That tax never enters the Section 904 computation in the first place, so it cannot be limited, it cannot become an excess credit, and it cannot generate a carryover.

This is a permanent forfeiture, not a deferral. A taxpayer who excludes wages under the FEIE and pays substantial foreign tax on those same wages is not banking that tax for a future year; it is simply unavailable, forever, to the extent it is allocable to the excluded amount. Taxpayers who want to build or preserve a carryover in a high-tax country typically need to skip the FEIE and claim the foreign tax credit on the full amount of foreign source income instead, which is also the choice that keeps the refundable Additional Child Tax Credit available in years that matter.

How Should Expats in High Tax Countries Plan Around a Large Carryover?

The practical goal is finding a year where the Section 904 limitation for the category has room left over after that year's own foreign tax is applied, because that leftover room is what pulls in an old carryover. A year where your foreign tax rate on that category of income drops relative to your U.S. rate, whether from a move to a lower tax country while foreign source income continues, a change in income mix, or added U.S. source income that raises the U.S. tax base without a matching rise in foreign tax, is the kind of year that finally absorbs a balance that has been sitting on Schedule B.

Expats in countries such as the United Kingdom or Germany, where income tax rates commonly run above U.S. rates on the same income, are the taxpayers most likely to bank a large carryover in the general or passive category. The ten year window is generous, but it is not indefinite, and a carryover that originated early in an assignment abroad can expire before a lower tax year ever materializes if nobody is tracking the clock. Reviewing the Schedule B balances every year, by category and by year of origin, is the only way to know whether a carryover is close to expiring and whether a specific year's plan, such as timing a Roth conversion, a bonus, or a change in residence, would put U.S. tax otherwise owed on the general or passive category in reach of an old, unused credit.

Bottom Line

A foreign tax credit that exceeds the Section 904 limitation is not wasted; it carries back one year and forward ten, but strictly inside the same separate limitation category, and it only survives on paper if it is reconciled on Form 1116 Schedule B every year it exists. The one exception that erases a carryover outright is choosing the FEIE over the credit, which permanently forfeits any credit tied to the excluded income under IRC Section 911(d)(6).

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Official IRS and Government Sources

• IRS, Foreign Tax Credit, Publication 514
• IRS, Instructions for Form 1116
• IRC Section 904, Limitation on Credit
• IRC Section 911, Citizens or Residents of the United States Living Abroad
• IRC Section 6511, Limitations on Credit or Refund
• Treas. Reg. Section 1.904-4, Separate Application of Section 904 With Respect to Certain Categories of Income
• IRS Tax Treaty Documents