What is the domestic content bonus adder?

The domestic content bonus adder is a 10-percentage-point boost to the Investment Tax Credit (ITC) or a 10% increase to the Production Tax Credit (PTC) for clean energy projects that meet US-sourcing requirements for steel, iron, and manufactured products. For ITC projects, that takes the base credit from 30% to 40%.

How long is documentation kept?

All domestic content compliance documentation must be retained for the full tax credit recapture period, which is five years from the project's placed-in-service date for the ITC. Empact stores all supplier data and certified compliance records securely for the full recapture window.

How long does an Empact domestic content review take?

Timing depends on project size, supplier count, and pathway. A typical project takes 8 to 12 weeks from kickoff to a certified compliance report, with supplier outreach and data collection accounting for most of the calendar time. Empact begins outreach in parallel with the project schedule so the certification is ready when your tax counsel needs it.

Domestic Content Compliance

Miss the domestic content requirements and you leave a 10% tax credit adder on the table.

The domestic content bonus adder adds 10 percentage points to your investment or production tax credit, but only if your steel, iron, and manufactured products meet US-sourcing requirements. Empact verifies, documents, and certifies your project's domestic content so the adder is captured and protected.

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10%

Bonus adder on top of your ITC or PTC

100%

US-manufactured requirement for steel and iron

5 yr

Tax credit recapture window for documentation

Compliance pathways: APR or Safe Harbor

What's at Stake

The 10% domestic content adder is valuable, but the documentation requirements are demanding.

The domestic content bonus adder increases your ITC from 30% to 40% or your PTC by 10%, but only if your project can demonstrate that all steel and iron is US-manufactured and that manufactured products meet domestic content thresholds.

Documentation must be collected directly from suppliers, many of whom are reluctant to share confidential cost and manufacturing information with their customers. Empact acts as a trusted third-party intermediary, collecting and securing supplier data without exposing confidential information.

Empact documents domestic content correctly from day one, so the full value of the adder is captured and protected.

Your suppliers' data stays confidential. Your compliance record stays complete.

Step 1, Empact requests

Data collected directly from your suppliers, not through your team.

Step 2, Empact reviews

Cost and manufacturing data validated in a controlled environment. Your team never sees raw supplier data.

Step 3, You receive

A certified compliance record. No confidential supplier information exposed.

The Two Compliance Pathways

Your project qualifies for the domestic content adder under one of two compliance pathways.

Adjusted Percentage Rule (APR)

A full cost analysis of manufactured products determines your domestic content percentage.

Under the APR, Empact collaborates with your EPC to identify all applicable manufactured products, works directly with suppliers to capture confidential cost and manufacturing data, and calculates your project-level domestic content percentage under Notice 2023-38.

Safe Harbor

Qualifying projects can use IRS-approved safe harbor tables to demonstrate compliance.

Under the Safe Harbor pathways in Notice 2024-41 and Notice 2025-08, Empact collects and reviews all manufactured product and component origin information and calculates your project-level domestic content percentage using the approved tables.

At a Glance, APR vs. Safe Harbor

	Adjusted Percentage Rule	Safe Harbor
Governing guidance	IRS Notice 2023-38	IRS Notice 2024-41, Notice 2025-08
Calculation method	Direct cost analysis of each manufactured product	IRS-approved cost tables applied to covered technologies
Eligible technologies	All applicable clean energy technologies	Solar PV, onshore wind, and BESS (per current notices)
Supplier data required	Confidential direct cost and manufacturing data	Origin information against the safe harbor tables
Typical complexity	Higher, with full project-level cost build-up	Lower, with standardized inputs
Best for	Projects with custom configurations or technologies outside safe harbor	Standard solar, wind, and storage projects seeking faster certification

Recent Regulatory Updates

Domestic content guidance has evolved rapidly. Empact tracks each change so your compliance position stays current.

May 2023

Notice 2023-38

Established the original Adjusted Percentage Rule (APR) framework and the steel and iron 100% requirement for the domestic content bonus credit.

May 2024

Notice 2024-41

Introduced the first Safe Harbor cost tables for solar PV, onshore wind, and battery energy storage systems, simplifying compliance for standard project configurations.

January 2025

Notice 2025-08

Updated the Safe Harbor tables with revised cost percentages and expanded technology coverage, refining how qualifying projects can demonstrate compliance without full cost build-ups.

August 2025

OBBBA transition

The One Big Beautiful Bill Act introduced new thresholds and restrictions for projects beginning construction after August 2025, including FEOC supply chain requirements that intersect directly with domestic content documentation.

Ongoing

Escalating thresholds

The applicable percentage for manufactured products escalates each year through the statutory schedule. Projects must meet the threshold in effect on their beginning of construction date.

Your domestic content is verified. Your suppliers' data stays confidential.

Collect & Verify

Empact works directly with your suppliers to collect manufacturing origin and cost data, acting as a trusted third-party intermediary so confidential information is never shared with your customers or competitors.

Calculate & Document

We aggregate domestic content information across all manufactured products, calculate your project-level percentage under the applicable pathway, and produce a fully documented compliance record.

Certify & Protect

Empact delivers a certified domestic content compliance report, giving your tax counsel and tax equity the documented evidence they need to claim the adder and defend it under IRS scrutiny.

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The Empact Engagement

A defined process from kickoff to certified record, built around your project schedule.

Kickoff

Review project scope, supplier list, and applicable pathway.

Supplier Outreach

Empact contacts each supplier directly with secure data-collection templates.

Data Collection

Cost, origin, and component data captured in a controlled environment.

Calculation

Project-level domestic content percentage calculated under APR or Safe Harbor.

Certification

Certified compliance report delivered for tax counsel and tax equity.

Recapture-Period Records

Documentation maintained securely for the full 5-year recapture window.

The Steel & Iron Requirement

Each structural steel and iron component must be 100% US-manufactured, no exceptions.

Key Rule

100% domestic, no percentage threshold.

Unlike manufactured products, there is no percentage threshold for structural steel and iron. Any foreign-sourced steel or iron used as a construction material disqualifies that component from the domestic content adder.

Empact's Role

Full documentation, collected and certified.

Empact collects and reviews all structural steel and iron documentation to confirm the 100% requirement is met, and maintains all records for the full tax credit recapture period.

Who Empact Works With

Domestic content compliance touches each stakeholder in the project capital stack.

Solar Developers

Utility-scale and DG portfolios

Wind Developers

Onshore and offshore projects

Storage Developers

Standalone and hybrid BESS

EPCs

Supply chain documentation support

Tax Equity Investors

Defensible compliance records

Domestic content compliance requires supplier relationships most project teams don't have.

Trusted third-party intermediary

Suppliers are often unwilling to share confidential cost and manufacturing data directly with developers. Most compliance approaches put your team in the middle of that conversation. Empact acts as a neutral third party, collecting and securing the data directly from suppliers without exposing sensitive information to your team or competitors.

Built for the complexity of clean energy compliance.

We don't hand you a checklist. We conduct the full review, calculate the domestic content percentage, and deliver a certified compliance report your tax counsel can rely on.

Connected to your full compliance picture

Domestic content intersects with FEOC supply chain requirements and BOC documentation. Empact manages all six compliance areas from a single platform, so nothing falls through the cracks.

What Empact Delivers

Everything your tax counsel, investors, and insurers need, delivered audit-ready.

All structural steel and iron documentation collected and verified as 100% US-manufactured

Manufactured product origin and cost data collected directly from suppliers

Project-level domestic content percentage calculated under APR or Safe Harbor

Certified domestic content compliance report ready for formal tax opinions

All supplier data securely stored for the full tax credit recapture period

FAQ

Common questions about the domestic content adder.

The Adjusted Percentage Rule (APR) under Notice 2023-38 requires a full cost analysis of each manufactured product to calculate a project's domestic content percentage. The Safe Harbor pathways under Notice 2024-41 and Notice 2025-08 use IRS-approved cost tables, removing the need for confidential supplier cost data on covered technologies. Safe Harbor is generally faster and lower-burden, but it is not available for all project types.

Eligibility depends on project type, placed-in-service date, and the percentage of domestic content in your manufactured products. All structural steel and iron must be 100% US-manufactured without exception. Manufactured products must meet a percentage threshold that escalates over time. Empact reviews your supplier base and project specifications to confirm eligibility before formal documentation begins.

Suppliers must provide manufacturer name, country of incorporation, and detailed cost or origin information for each manufactured product and component. Under APR, this includes confidential direct cost data. Under Safe Harbor, suppliers provide origin information against the IRS-approved tables. Empact collects this data directly so confidential information never passes through your team or competitors.

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FEOC

The 10% adder is worth capturing. Let's make sure your project qualifies.

Empact's domestic content team is ready to begin working with your suppliers, verifying your documentation, and delivering a certified compliance report, so the adder is captured and defensible.