If you were planning to put solar panels on your warehouse, retail store, or office roof this year and the July 4, 2026 construction deadline came and went without a signed contract, you're probably assuming the tax credit is gone. It isn't — but the math changed, and the new timeline is a lot less forgiving.
Here's the short version: business owners who started construction on a solar project by July 4, 2026 locked in a 30% federal tax credit with roughly four years to finish the job. If you missed that date, the credit is still available under Section 48E of the tax code, but now your entire system has to be up and running — not just under contract, not just permitted, but generating electricity — by December 31, 2027. Miss that, and the federal credit disappears entirely, not just shrinks.
That's an 18-month runway from today, and commercial solar installs routinely take that long once you account for utility interconnection queues, permitting, and equipment lead times. So "what's left" is real, but it's a sprint, not a stroll.
Why July 4, 2026 Mattered in the First Place
The One Big Beautiful Bill Act (OBBBA), signed into law on July 4, 2025, restructured the clean-energy tax credits that had been running under the Inflation Reduction Act. Instead of a long phase-down through the early 2030s, OBBBA drew a hard line: solar and wind projects needed to begin construction within one year of enactment — July 4, 2026 — to keep the old, more generous rules.
"Beginning construction" isn't a marketing phrase; it's a defined tax term with two ways to satisfy it:
- The Physical Work Test — starting physical work of a significant nature on-site (racking, mounting structures) or off-site (a manufacturer building your specific equipment under contract).
- The Five Percent Safe Harbor — for smaller projects (roughly 1.5 MW and under, which covers the vast majority of commercial rooftop and ground-mount installs), simply incurring or paying 5% of the total project cost by the deadline was enough to lock in construction-start status.
Projects that cleared either test by July 4, 2026 get the traditional four-year continuity safe harbor — meaning the system can be completed as late as 2030 and still claim the credit at the higher rate, with some room for excusable delays (permitting fights, supply chain issues, and the like).
What Happens If You Missed It
If your project didn't begin construction by that date, Section 48E is still on the books for you — but the safe harbor is gone. The replacement rule is blunt: the system must be fully placed in service by December 31, 2027. Not permitted, not delivered, not "substantially complete" — generating power and interconnected to the grid.
There's no partial credit for a project that's 90% finished on January 1, 2028. It's full credit or nothing, which makes the next 18 months a hard deadline rather than a soft target.
Practically, that means:
- Get your interconnection application in now. Utility interconnection studies are frequently the longest pole in the tent, sometimes taking 6–12 months in congested territories. This step alone can eat a third of your remaining runway.
- Lock equipment and installer capacity early. Panel and inverter lead times fluctuate, and installers with unfilled 2027 calendars are going to get booked up fast as more businesses realize the same deadline applies to them.
- Build in schedule slack for permitting. Local jurisdictions vary wildly in permit turnaround; don't assume your city moves at the same pace as the case study in your installer's sales deck.
The Credit Itself: Base Rate vs. the Rate Most Businesses Actually Get
Section 48E's statutory base rate is only 6% of qualified basis. Almost nobody pays 6%, though — the credit jumps to 30% if the project satisfies prevailing wage and apprenticeship (PWA) requirements during construction. Here's the part that matters for most small business owners: projects under 1 megawatt are exempt from the PWA requirement and automatically qualify for the full 30% rate. Since most commercial rooftop solar for a single warehouse, restaurant, or retail location falls well under that threshold, most readers of this article are looking at 30% regardless.
On top of the base 30%, several bonus adders can stack:
- Domestic content bonus (+2 to +10 percentage points) for using U.S.-manufactured steel, iron, and a threshold percentage of manufactured components.
- Energy community bonus (+2 to +10 points) for projects sited in areas tied to fossil fuel employment or brownfield sites.
- Low-income community bonus (up to +20 points, allocated through a separate application process, not automatic).
Stacked fully, some projects can approach a 70% effective credit rate — though the domestic content and low-income adders require documentation most small businesses will want their installer or CPA to help assemble.
Depreciation Still Does Heavy Lifting
The tax credit gets the headlines, but accelerated depreciation is often worth nearly as much in present-value terms. Solar equipment qualifies for a five-year MACRS recovery schedule, and OBBBA restored 100% first-year bonus depreciation for qualifying property placed in service after January 19, 2025. Combined with the 30% ITC, many commercial owners end up recovering close to half the system's cost through tax benefits in year one alone — which is a big part of why the July 4 deadline generated so much scrambling in the first place.
One coordination note: when you claim the ITC, you must reduce your depreciable basis by half the credit amount (a long-standing rule, not new to OBBBA). Your accountant needs to run this basis reduction correctly, or you'll overstate depreciation and create a problem at audit.
Don't Want to Own the Tax Credit? You Can Sell It
Not every small business has enough tax liability to fully use a large ITC in one year. Section 6418 transferability — also preserved under OBBBA — lets an eligible business sell all or part of its tax credit to an unrelated third party for cash, generally at a modest discount to face value. This turns a credit that might otherwise sit unused (subject to carryforward rules) into immediate cash that can help fund the project itself. If your business runs close to break-even or has volatile income, ask your tax advisor whether transferability makes more sense than trying to absorb the full credit yourself.
The FEOC Compliance Trap Nobody Mentions Until It's Too Late
OBBBA also introduced "Foreign Entity of Concern" (FEOC) restrictions that apply for a full decade after you claim the credit — not just at the moment of installation. If a Specified Foreign Entity gains effective control over the project (through certain licensing, financing, or long-term service arrangements) within ten years of claiming the credit, the IRS can claw back the entire ITC amount. This isn't a one-time procurement checkbox; it touches ongoing operations and maintenance contracts and equipment warranty arrangements for years after the ribbon-cutting. Read any long-term service agreement or extended warranty with this in mind, and have your tax counsel review vendor relationships before you sign, not after.
Keeping the Financial Picture Clean Through a Multi-Year Project
A solar installation that spans a construction period, a placed-in-service date, a tax credit claim, a basis reduction, and possibly a credit sale under Section 6418 touches your books in a lot of places over 18 months. Getting the sequence right — capitalizing costs correctly during construction, recording the credit and the associated basis adjustment in the right period, and tracking any FEOC-related contract terms for the following decade — is exactly the kind of multi-year, auditable trail that's easy to lose in a spreadsheet and hard to reconstruct later if the IRS asks questions.
Beancount.io gives you plain-text, version-controlled accounting where every capital expenditure, credit claim, and depreciation schedule is a durable, diffable record rather than a cell that can be silently overwritten. If you're navigating a project with this many moving tax pieces, having a ledger you can hand to your CPA — and audit yourself, line by line, years later — is worth setting up before the first invoice arrives. Get started for free and see why business owners are choosing transparent, plain-text books over black-box software.