Filed an Extension? You Have One Clean Shot at the R&D Credit This Fall

TL;DR

• If your business extended its 2025 return, the upcoming fall deadlines are your last chance to claim the R&D credit on an originally filed return rather than through an amended one.
• The original return is the cleaner path: amended refund claims carry additional IRS documentation requirements that an original filing does not.
• 2025 returns are also the first filed under restored domestic R&D expensing, and the detailed Section G reporting on Form 6765 is still optional this year, which makes this a favorable filing season to get the credit right.

Extension season has a rhythm. The spring deadline passes, the pressure drops, and the extended return sits quietly until fall forces the issue. For calendar-year businesses, that generally means mid-September for partnerships and S corporations and mid-October for C corporations. If your company does technical work and has never claimed the research credit under IRC Section 41, the weeks before those deadlines matter more than most owners realize.

Why the original return is the cleaner path

There are two ways to claim the R&D credit for a tax year: on the return you originally file, or later, by amending. Both are legitimate. They are not equally pleasant. When the credit rides on your original return, it is simply part of the filing. When it arrives later as a refund claim on an amended return, the IRS requires specific supporting information up front, and the claim gets a level of scrutiny an original filing does not attract. Timing also differs: a credit on the original return reduces what you owe now, while an amended claim means waiting on processing and a refund.

None of that makes amending wrong. It makes the extension window valuable. An extension is, in effect, a second chance to put the credit where it belongs the first time. Once the extended return is filed, that chance is gone for the year.

Why this particular fall is worth the effort

Two things make the 2025 filing season, playing out now for extended filers, unusually favorable. First, 2025 returns are the first filed under the restored current-year expensing of domestic research costs, enacted in 2025 legislation. Businesses that had been amortizing domestic R&D expenses may find the overall math of doing an R&D study more attractive than it has been in years, and certain smaller businesses may also have retroactive options for prior years worth discussing with a tax advisor.

Second, the IRS has been expanding what Form 6765 asks of credit claimants. Per the IRS instructions for Form 6765, the detailed business-component reporting in Section G remains optional for tax year 2025 but becomes mandatory for many filers starting with tax year 2026. Claiming this year means filing under the lighter reporting regime while building the project-level records the stricter one will expect.

Does your work even qualify?

The credit applies well beyond laboratories. Under Treasury Regulation 1.41-4, qualifying work generally involves developing or improving a product or process where the technical outcome was uncertain and your team worked through alternatives to resolve it. That pattern shows up in software development, engineering design, custom manufacturing, systems integration, boat building, automation work, and plenty of other places that do not call what they do "research." Whether specific activities qualify depends on the facts and the documentation behind them.

What starting now actually involves

Less than the deadline pressure suggests. The initial assessment, which tells you whether a credit is worth pursuing at all, costs $0 and asks little of your team. If the numbers justify a study, Strata typically completes the work in 4 to 8 weeks depending on complexity and responsiveness, with most of the workload sitting on our side. Starting in late summer means the work fits comfortably inside the extension window and your team's fall stays focused on your business, not on tax paperwork. Strata also works directly with your CPA, so the credit lands in the extended return without you playing go-between.

If the window closes anyway

Missing the extension deadline does not erase the opportunity. Prior years generally remain open to amended claims within the statute of limitations, and a current-year claim can always be built into next year's filing from the start. The fall deadline is not the last chance. It is just the best one available right now.

If your business is sitting on an extended return and unclaimed technical work, the assessment costs nothing and the calendar is cooperative for a few more weeks. Contact Strata R&D Tax Group to find out what you have.

This post is for informational purposes only and does not constitute tax or legal advice. Consult a qualified tax professional regarding your specific circumstances.