After the July 6 Section 174A Deadline: What Happens Next?

Your Section 174A filing is complete. What happens next depends on what the filing actually changed.

That distinction matters because two separate rules can be involved. Section 174A controls the treatment of domestic research and experimental expenditures. Section 41 controls the research credit. A company may amend a return for Section 174A only, for Section 41 only, or for both provisions at the same time.

The IRS's special research-credit refund process does not automatically apply just because an amended return involves R&D spending. It applies when the filing requests a refund based on a new or increased Section 41 credit.

Here is how to identify the process that applies, track the filing, prepare for IRS questions, and protect the remaining deadlines.

For the retroactive election, Rev. Proc. 2025-28 generally defined a small business taxpayer as a taxpayer that was not a tax shelter and met the Section 448(c) gross-receipts test for its first tax year beginning after December 31, 2024. For a tax year beginning in 2025, that test generally used average annual gross receipts of no more than $31 million for the three prior tax years, subject to aggregation and other applicable rules.

First, identify what your filing changed

Before estimating a timeline, confirm which of these paths applies:

This is more than terminology. A Section 174A deduction-only amendment does not become a Section 41 research-credit claim merely because both provisions relate to R&D.

If your filing changed the research credit, however, the IRS will review whether the claim contained the required factual information before considering its merits.

How long does an amended return take?

There is no single processing estimate that applies to every entity and every form.

If you filed Form 1040-X

The IRS says a Form 1040-X generally takes 8 to 12 weeks to process and may take up to 16 weeks in some cases. The Where's My Amended Return? tool normally shows a filing about three weeks after submission and covers the current tax year plus three prior years.

The tool does not track business returns, carryback applications, claims handled by certain specialized units, or several other listed categories.

If a corporation or other business entity filed

The IRS does not publish the same 8-to-12-week promise for every business amended return. Processing times vary by form, filing method, issue, and whether the return requires correspondence, classification, examination, or Joint Committee review.

Use the IRS processing-status dashboard for current backlog information. Your tax professional can also monitor account transcripts and IRS correspondence. If you do not have transcript access set up, your accountant or your R&D credit consultant can pull the account transcripts for you and watch for movement. For pass-through businesses, make sure the entity-level filing and any owner-level amended returns or other required adjustments remain coordinated.

If the filing includes a Section 41 refund claim

The IRS says it will make every attempt to determine a research-credit refund claim within six months of receipt. That is a target for a determination, not a guarantee that a check will arrive within six months. It also does not apply to a Section 174A deduction-only amendment.

What do Letters 6426C and 6428 mean?

Letter 6426C or Letter 6428 means the IRS believes a refund claim involving the Section 41 research credit is missing required information.

For claims subject to the IRS's June 18, 2024 change, three substantive items must be provided with the claim:

1. Every business component to which the Section 41 claim relates for that year.
2. The research activities performed for each business component.
3. Total qualified employee wage expenses, supply expenses, and contract research expenses for the claim year.

The filing must also include the required declaration under penalties of perjury. In many cases, the signature on the amended return serves that function.

Some IRS materials still refer to the historical "five items" standard. The two items the IRS removed from the initial filing requirement were:

• The names or titles of the individuals who performed each research activity.
• The information each individual sought to discover.

The IRS can still request those details if the claim is examined, so they should remain in the supporting file.

The 45-day response period

The IRS has extended the research-credit claim transition period through January 10, 2027. During that period, a Letter 6426C or 6428 identifies the missing information and gives the taxpayer 45 days to perfect the claim. Use the deadline printed in the letter.

The IRS says fax is the preferred response method, although a response may also be mailed. Include a copy of the letter and answer the identified deficiencies with facts. Repeating the statutory four-part test or quoting regulations without tying them to the company's work is not sufficient.

If the IRS does not receive a timely, adequate response, its FAQ states that the entire refund claim will be rejected. The IRS Independent Office of Appeals does not consider claims rejected as deficient or otherwise not processible.

If a claim is rejected while the applicable refund statute is still open, qualified counsel should immediately determine whether a new, complete claim can be filed before the deadline. Do not assume a rejected claim preserved the year.

What affects the refund timeline?

Four factors usually matter most.

1. The form and current IRS backlog

Individual and business amended returns move through different systems. Check the live IRS processing dashboard instead of applying the Form 1040-X estimate to every entity.

2. Whether the Section 41 claim was complete

A filing that contains the required business-component facts and expense totals can move to substantive review. A deficient filing may stop while the IRS waits for a response.

3. Whether the refund exceeds the Joint Committee threshold

A qualifying net income-tax refund or credit of more than $2 million, or more than $5 million for a C corporation, requires IRS review and a report to the Joint Committee on Taxation before payment.

The IRS determines the threshold on a net basis and considers the same taxpayer's returns being reviewed. A Joint Committee case is assigned to an IRS examiner and may be examined or surveyed. Federal law generally prevents payment until 30 days after the IRS submits its report to the Joint Committee.

This is a statutory oversight process, not an allegation that the claim is improper, but it adds steps and can extend the timeline.

4. Whether another issue affects the account

Refunds applied to other tax balances, entity-owner mismatches, inconsistent amended returns, missing signatures, carrybacks, and other account conditions can delay or change the amount ultimately paid.

Does the IRS pay interest on the refund?

Generally, yes. Section 6611 provides interest on tax overpayments, and the IRS calculates the amount when it issues or credits the refund.

The calculation is more nuanced than multiplying the refund by one current rate. Start and stop dates depend on when the tax was paid, when the original and amended returns were filed, when the claim became processible, and when the refund is scheduled. A statutory 45-day rule can also limit interest for part of the period.

For amounts bearing interest during the quarter beginning July 1, 2026, the annual rates are:

• 7% for noncorporate taxpayers.
• 6% for corporations.
• 4.5% for the portion of a corporate overpayment above $10,000 for a taxable period.

Interest compounds daily, and the IRS resets the rates quarterly. Do not forecast the final payment by applying 7% to the entire refund for the entire period.

Build the right examination file now

The documentation file should match the filing. If the amended return changed both Section 174A and Section 41, maintain both workstreams.

Section 174A file

Keep:

• The domestic R&E computation by legal entity, tax year, general-ledger account, and cost category.
• Support for the classification of domestic versus foreign research expenditures.
• The original Section 174 amortization schedules and the revised deduction or recovery calculation.
• The Rev. Proc. 2025-28 election statements, method-change statements, and proof of timely filing.
• The Section 280C treatment and a reconciliation to Form 6765, where applicable.
• Amended Schedules K-1, owner-level changes, and state-return effects, where applicable.

Section 41 file

Keep:

• Every business component included in the claim.
• The research activities performed for each component.
• The technical uncertainty and process of experimentation supporting each component.
• The names or titles of the people who performed the work and the information they sought to discover.
• Qualified wage, supply, computer-rental, and contract-research support tied to the tax return.
• Controlled-group, pass-through, base-period, and credit-allocation workpapers, where applicable.

Payment of a refund is not a substantive approval of every position in the filing. The IRS can later examine the claim. An excessive income-tax refund claim may also be subject to a 20% penalty under Section 6676 unless the excessive amount is due to reasonable cause. Good records can help support the filing and a reasonable-cause position, but the penalty analysis depends on all facts and circumstances.

Prepare now for Form 6765 Section G

Section G of Form 6765 is optional for tax years beginning before 2026. For tax years beginning after 2025, it is generally required unless an exception applies.

The exceptions include certain qualified small businesses making the payroll-tax credit election and, on an original return, taxpayers with no more than $1.5 million of controlled-group QREs and no more than $50 million of average annual gross receipts under the form's rules.

When Section G is required, the current instructions generally require business-component reporting for at least 80% of total QREs, capped at the top 50 business components. The business-component file built for an amended research-credit claim can become the foundation for this reporting, but the requirements are not identical.

What if the IRS denies the claim?

Do not confuse a rejection with a disallowance:

• A deficient or otherwise nonprocessible research-credit refund claim may be rejected without Appeals consideration.
• A claim considered and denied in full or in part may receive a statutory notice of claim disallowance, commonly Letter 105-C or 106-C.

When the IRS mails a statutory notice of claim disallowance, Section 6532 generally provides two years from the mailing date to file a refund suit in the appropriate U.S. district court or the U.S. Court of Federal Claims.

Requesting reconsideration or review by the IRS Independent Office of Appeals does not suspend that two-year period. Calendar the date immediately and keep it separate from any 30-day administrative response period shown in the letter.

The taxpayer and IRS may agree in writing to extend the period using Form 907, but both parties must sign before the period expires. Submitting Form 907 is not enough; the extension is not effective until the IRS countersigns it.

If the IRS has taken no action on a valid refund claim, federal law generally allows a refund suit after six months have passed, subject to the other jurisdictional requirements. Litigation is not the routine next step, but a stalled or disallowed claim should be reviewed by qualified tax controversy counsel well before any deadline approaches.

What if you missed the July 6 deadline?

The special retroactive Section 174A election is closed, but other planning paths may remain.

Recover the remaining unamortized domestic R&E balance

For domestic R&E expenditures capitalized under the 2022 through 2024 rules, a taxpayer may elect to recover the remaining unamortized amount:

• In full in the first tax year beginning after December 31, 2024; or
• Ratably over the two-tax-year period beginning with that year.

Rev. Proc. 2025-28 provides the applicable accounting-method procedures. The right choice depends on the taxpayer's return status, projected taxable income, limitations, ownership, and state treatment. It should not be described as economically identical to a prior-year refund.

Review open years for the Section 41 research credit

The July 6 deadline did not replace the normal refund statute for a Section 41 claim. A refund claim is generally due by the later of:

• Three years from the date the original return was filed; or
• Two years from the date the tax was paid.

Separate lookback rules limit the amount that can be refunded. For many calendar-year taxpayers, 2023 and 2024 remain open. Some taxpayers that filed 2022 returns on extension may also still have time, but the exact deadline depends on the filing and payment history.

Open does not mean unchanged. The special window for a late Section 280C(c)(2) reduced-credit election also closed on July 6. A taxpayer now adding a research credit on an amended return generally cannot add that election and may instead need to reduce the related expense deduction or capital account. Model the net federal and state benefit before filing.

Apply Section 174A correctly going forward

Section 174A allows a current deduction for qualifying domestic R&E expenditures paid or incurred in tax years beginning after December 31, 2024, unless the taxpayer elects an eligible capitalization and amortization method. Foreign research expenditures remain subject to the separate 15-year capitalization rule under Section 174.

Your next 90 days

Days 1 to 30: confirm and classify

• Save proof of filing and delivery for every amended return or administrative adjustment request.
• Confirm whether each filing changed Section 174A, Section 41, Section 280C, or a combination.
• Reconcile entity-level changes to amended Schedules K-1 and owner returns.
• Route every IRS letter to the tax team on the day it arrives.

Days 31 to 60: build the response file

• Pull available account transcripts and check the appropriate IRS status tool.
• Complete the Section 174A roll-forward and domestic-versus-foreign support.
• Complete the Section 41 business-component narratives and QRE support.
• Calendar each open-year refund statute separately.

Days 61 to 90: prepare for the next filing cycle

• Resolve any inconsistency between the amended filing, payroll records, general ledger, Forms 6765, and state returns.
• Confirm the 2025 treatment of the remaining unamortized domestic R&E balance.
• Test whether Form 6765 Section G will be required for the 2026 tax year.
• If a disallowance arrives, calendar the two-year suit period immediately and involve tax controversy counsel.

Disclaimer: This article is for general informational purposes only and does not constitute tax, legal, or accounting advice. Tax deadlines and procedural rights depend on the taxpayer's facts, filing history, entity structure, and applicable law. Consult a qualified professional regarding your situation.

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