The Ratio That Decides Whether Your Tax Credit Exists

Inside the 2025 reconciliation act — Public Law 119-21, 139 Stat. 72, enacted July 4, 2025, commonly known as the One, Big, Beautiful Bill Act — sit two definitions that now underlie every clean-electricity credit in the Code. Section 7701(a)(51) defines the prohibited foreign entity. Section 7701(a)(52) defines material assistance from one, and reduces it to a single fraction: the material assistance cost ratio. For any qualified facility or energy storage project that begins construction after December 31, 2025, that fraction determines whether the §45Y or §48E credit exists. Not its size. Its existence.

The arithmetic is unforgiving

The ratio itself is plain: the direct costs of manufactured products in the facility that were not mined, produced, or manufactured by a prohibited foreign entity, over the total direct costs of all manufactured products. What makes it consequential is the threshold schedule the statute attaches, keyed to the calendar year construction begins. Qualified facilities must clear 40 percent for 2026 construction, rising to 45, 50, 55, and 60 percent for construction after 2029. Energy storage runs a steeper track: 55 percent for 2026, ratcheting to 75. Section 45X components carry their own schedules, keyed to the year of sale.

And the consequence of failure is not a haircut. The statute's mechanism is definitional: a facility whose construction includes material assistance from a prohibited foreign entity is excluded from the definition of "qualified facility" altogether. The credit is not reduced — the thing that generates it ceases to exist. A storage supply chain that comfortably clears this year's threshold fails 2029's unchanged, because the ratchet is written into the statute, not left to regulation.

Miss the ratio by a single point and the credit is not smaller. It is gone — the statute removes the facility from the definition that creates it.

Who counts as prohibited

The entity tests run in two layers. Specified foreign entities come off statutory watchlists — the 2021 NDAA foreign-entity-of-concern definitions, the §1260H Chinese-military-company list, entities tied to the Uyghur forced-labor architecture, the FY2024 NDAA §154(b) designations, and foreign-controlled entities. Then comes the layer that reaches ordinary commercial structures: the foreign-influenced entity. An entity is caught if a specified foreign entity can appoint a covered officer; if a single one holds 25 percent or more of it; if several together hold 40 percent; if they hold 15 percent of its debt; or if, in the prior year, it made a payment to a specified foreign entity under an arrangement conferring effective control.

Effective control is where the statute leaves the cap table and enters the contract file. Under the statutory interim definition, it includes unrestricted rights over production quantity or timing, designation of output offtake, restriction of access to data or sites, and exclusive operation and maintenance. For intellectual-property licenses entered into or modified on or after July 4, 2025, it extends further: source-direction rights, operational direction, restrictions on use — and structural terms such as royalties running beyond year ten, service agreements longer than two years, or an incomplete technology transfer that leaves the licensee unable to produce without the licensor's continued involvement. A royalty tail in year eleven of a license signed last autumn is now a fact about your tax credit. This is contract diligence, not merely ownership screening.

Interim rules, dated clocks

The operative guidance is IRS Notice 2026-15 (February 12, 2026) — and it is, by its own terms, interim: a description of forthcoming proposed regulations, paired with safe harbors a taxpayer may use in the meantime. There are three. An Identification Safe Harbor lets the taxpayer use the domestic-content tables of Notices 2023-38, 2024-41, and 2025-08 to identify manufactured products and components. A Cost Percentage Safe Harbor lets those tables' deemed percentages stand in for supplier cost data no supplier wants to disclose. A Certification Safe Harbor lets the taxpayer rely on supplier certifications that meet the statutory specification. Every element of this structure should be read with its label attached: interim, pending proposed regulations, subject to refinement — though the threshold percentages themselves are statutory and will not move by regulation.

The reliance windows are dated. Taxpayers may rely on the notice until sixty days after the proposed regulations publish, and on its tables until sixty days after Treasury issues the statutory safe-harbor tables — which the statute requires by December 31, 2026. The notice also expressly defers guidance on who qualifies as a prohibited foreign entity, leaving entity status a legal determination without an administrative list behind it.

One further trap for sophisticated parties: there are now two coexisting beginning-of-construction regimes. For prohibited-foreign-entity purposes, the statute fixes beginning of construction to the Notice 2013-29/2018-59 rules as they stood on January 1, 2025. The wind-and-solar termination deadline, by contrast, runs on Notice 2025-42's tightened physical-work rules. The same phrase, two different legal tests, on the same project — and the parties most likely to get it wrong are the ones confident they already know what "begun construction" means.

The certification is the load-bearing document

The supplier certification the statute contemplates is not a comfort letter. It must carry the supplier's EIN, be signed under penalties of perjury, state that the property was not produced by a prohibited foreign entity and that the supplier does not know or have reason to know that any prior supplier in the chain of production is one, state the non-PFE cost figures — and be retained by both supplier and taxpayer for at least six years, producible to the IRS on request.

The taxpayer's side is governed by the knowledge-taint rule: if the taxpayer knows or has reason to know a product was PFE-produced, its entire direct cost counts against the ratio, and a certification the taxpayer had reason to doubt provides no protection at all. "Reason to know" is a diligence standard — which means documented, third-party diligence is precisely what converts a stack of certifications into an actual defense.

The penalty architecture explains why this file is worth building carefully. Section 6662(m) drops the substantial-understatement threshold to 1 percent of tax for credits disallowed by an overstated ratio, making the 20 percent accuracy penalty nearly automatic. Section 6501(o) gives the IRS a six-year assessment window for ratio errors. New §6695B puts personal penalty exposure — the greater of 10 percent of the resulting underpayment or $5,000 — on any supplier whose certification it should have known was false causes a credit disallowance, for certifications issued after December 31, 2025. And on §48E projects, a payment conferring effective control to a specified foreign entity within ten years of placed-in-service recaptures 100 percent of the credit, with testing applying to taxable years beginning after July 4, 2027. That last provision quietly converts every ITC project into a decade-long contract-monitoring obligation.

The supplier signs under penalty of perjury. The taxpayer answers under a six-year statute. "Reason to know" is the phrase doing the work — and it is a diligence standard.

The credit buyer is the second audience

Under §6418, the buyer of a transferred credit bears the recapture risk on its portion and the excessive-credit-transfer liability — tax plus a 20 percent penalty — if the credit was overstated. Yet every fact that determines the credit's validity sits with the seller. The market has already priced that asymmetry: transfer agreements in 2026 carry explicit representations on foreign-entity status, ratio compliance, and certification accuracy, and buyers increasingly demand the underlying documentation rather than the representation alone. Tax-credit insurers underwrite from the same file. The evidence file is what the representation, the insurance policy, and the price all rest on — and a project that cannot produce one sells its credit at a discount, if it sells it at all.

What the file has to contain

This is the discipline Gatewell Federal runs: a supplier-bench screen that records ownership, debt, officer-appointment, and license-term facts against each statutory test; supplier certifications engineered to the statutory specification rather than downloaded from a template; a per-facility ratio workpaper with the safe-harbor elections documented; and six-year retention custody with an annual refresh — because every January 1 the threshold steps up for that year's new construction — and for §45X components, for that year's sales — so the ratio your supply chain produced for the last project is not the ratio the next one will be judged by. We report the facts against the statutory tests; whether an entity is a prohibited foreign entity as a matter of law, and whether a credit position holds, are questions for your tax counsel — answered from the file we build.

The ratio is arithmetic. The evidence behind it is where projects will succeed or fail — and the projects assembling it now, while the guidance is interim and the clocks have not started, are the ones that will clear the audit, the transfer, and the recapture window without drama.