Autumn Budget 2026 Announces Changes to the R&D Tax Credit Scheme

Budget 2026 leaves R&D tax credit rates exactly where they were, but it removes one of the biggest administrative hurdles introduced in 2023. From 1 April 2027, the Claim Notification Form (CNF) will no longer be required for R&D claims made on or after that date.

As a member of HMRC's R&D Communication Forum (RDCF), Myriad received HMRC's update on the Budget measures directly, with more details explained beyond what was available in the Autumn Budget.

This post sets out what is changing and what isn't, what we think the changes say about HMRC's direction of travel, and what you should do before the new rules take effect.

What is changing for R&D tax credits in Budget 2026?

The two changes announced are both about the claims process:

• The Claim Notification Form is being removed. The government will legislate in Finance Bill 2026-27 to remove the requirement for claims made on or after 1 April 2027. You may also know this form as the Advance Notification Form (ANF).
• The Additional Information Form is being rationalised. From autumn 2027, HMRC will rework the AIF to reduce unnecessary duplication, improve the information requested on contracting and externally provided workers, and give greater clarity on project information and the ERIS intensity ratio.

Neither change alters what qualifies as R&D or how your relief is calculated. Both change how much you have to do, and when, to get a claim accepted.

The rates are unchanged. The merged scheme still gives a 20% credit, worth around 15% net to a profitable company paying Corporation Tax at the 25% main rate, and ERIS continues to support loss-making, R&D-intensive SMEs.

What did HMRC tell the R&D Communication Forum?

HMRC's update to RDCF members explained why the CNF can go. The form was introduced in 2023 as part of a package to tackle high levels of error and fraud in R&D tax reliefs, alongside the AIF and stronger compliance activity. HMRC's conclusion is this:

"This means the government can now remove the CNF, while keeping other safeguards in place to identify and tackle incorrect claims."

This essentially means HMRC believes the 2023 measures have worked. The CNF was one gate among several, and HMRC is now confident enough in the others to take it away.

What do the changes tell us about HMRC's direction?

Our reading is that this is a deliberate easing of the compliance regime. HMRC's latest R&D statistics show claims falling by 26% to 46,950, with SME claims down 31%. Some of that is the removal of ineligible claims, and some of it is the administrative burden itself. By removing the CNF, HMRC is signalling that the risk of spurious claims has come down far enough to lower the barrier to entry for smaller and first-time claimants.

It is not a retreat from enforcement. The AIF stays, and the Budget funds 670 additional HMRC compliance officers. What HMRC is doing is moving its scrutiny away from a form you complete before you claim and towards the quality of the claim you submit. Every other step HMRC described points the same way: an end-to-end review of the claims process, plans to simplify the legislation, and a targeted advance assurance pilot that is still open for applications.

Our view is that the claims process will keep getting lighter, but the evidence expected behind each claim will not. A clear project description and a cost trail you can defend matter more once the CNF is gone, because the AIF and the claim itself carry more of the weight.

Do you still need to submit a CNF now?

Yes, if it applies to you. HMRC has confirmed that the requirement remains in place for claims until 1 April 2027, and that claimants and agents must continue to pre-notify claims while it does. It doesn't matter when your accounting period ends, only when you submit the claim.

A software company with a 30 June 2026 year end has never claimed R&D tax relief before. Its notification deadline is 31 December 2026, which falls before the requirement is removed. Until the legislation is in place, it should submit the CNF by that date.

A manufacturer with a 31 March 2027 year end is also a first-time claimant. It can only make its claim after the period ends, so the claim will fall on or after 1 April 2027 and, therefore, will not need a CNF.

Where your position isn't clear, submitting is the safer route. A CNF you turn out not to need costs a few minutes. A missing one you did need invalidates the claim. In practice, this means:

1. Check whether the CNF applies to you, using Myriad's free Advance Notification Form Checker.
2. If your notification deadline falls before 1 April 2027, submit the form on time.
3. Submit your AIF before your Company Tax Return, as you do now. The AIF isn't going anywhere.

Do you still need to submit an AIF?

Yes. The AIF is unaffected by the removal of the CNF, and every R&D claim still needs one. It must be submitted to HMRC before your Company Tax Return (CT600), and if you file the CT600 without a valid AIF already on record, the claim is rejected and you'll need to resubmit both forms.

The new, rationalised form arrives in autumn 2027, so complete the current version for any claim you submit before then. HMRC has said the changes are about reducing duplication and improving clarity, so the work you put into clear project descriptions and a clean cost breakdown now will carry across to the new form.

What else is HMRC reviewing?

The CNF and AIF are the changes with dates attached, but HMRC also told RDCF members it will consider the R&D claims process end to end, aiming to cut unnecessary burdens while keeping the safeguards it needs. It also wants views on simplifying the R&D legislation itself, as part of the Budget's Corporate Tax Simplification for Business Investment work. Three areas are already on the list:

• The ERIS intensity ratio, where the definition of total expenditure and the aggregation rules are complex
• The PAYE/NIC cap, where the exemption meant to support smaller, growing businesses doesn't always apply
• Going concern status, which a company can lose for technical reasons even when a viable trade continues

HMRC is also reviewing whether its R&D Expert Advisory Panel is delivering its intended benefits at the midpoint of its two-year contract.

Key takeaways

• Rates are unchanged. The merged scheme and ERIS stay as they are, so the value of a claim hasn't moved.
• The Claim Notification Form is going, but not yet. It applies to claims made from April 2027, and HMRC has confirmed it must still be submitted until then.
• The Additional Information Form stays and gets simpler. Expect less duplication and clearer requirements on contracting, externally provided workers and project information from autumn 2027.
• HMRC's direction is clear. The claims process is being eased, but scrutiny is moving to the quality of the claim itself, so strong evidence matters more, not less.
• More simplification is coming. HMRC is gathering views on the ERIS intensity ratio, the PAYE/NIC cap and going concern status.

If you'd like to know how these changes affect your next claim, or whether a notification deadline applies to you, contact Myriad and we'll talk you through it.