When does HMRC launch an enquiry into an R&D tax relief claim?

Accountants are often asked by their innovative clients to provide reassurances on the success of an R&D tax relief claim when it is submitted to HMRC.

While you may be confident that everything was handled correctly, it is not possible to fully relax until you know that an enquiry is not heading your way.

Even getting the relief itself does not mean a claim is safe from enquiry, so it is important to understand how and when HMRC can launch an enquiry.

How long does HMRC have to launch an R&D tax relief enquiry?

While it might not feel like it when submitting an R&D tax relief claim, there is a point after which HMRC cannot launch an enquiry into a claim.

HMRC has, at most, 15 months to launch an enquiry into an R&D tax relief claim, though this can often be shorter.

The 15-month deadline is only applied to claims that are submitted alongside amended tax returns – even this may be shorter, as the deadline is the next quarter day after a 12-month period.

If you encourage clients to have their R&D tax relief claim ready to go by the time you file their original tax return, they will only face a 12-month window in which HMRC can launch an enquiry.

It is worth remembering that these thresholds are calculated based on the submission of the R&D tax relief claim instead of focusing on the date of the project itself.

In essence, this means that work completed in one accounting period might form part of an R&D tax relief claim that is submitted after the next accounting period and is only safe from enquiry a year or more after that.

Is an R&D tax relief claim safe from enquiry once the relief is given?

There is an unfortunate muddling of language when it comes to submitting an R&D tax relief claim that leads some to believe that something is safe from enquiry prematurely.

Just because a claim has been submitted and relief awarded does not mean the claim is successful.

The only time when you can categorically say that an R&D tax relief claim has been approved is when the deadline for enquiries passes and no matter is raised.

This means that innovative businesses risk investing funds into the business that may end up being recalled by HMRC.

It is worth noting that there are barriers to the extent of HMRC’s enquiries into historic claims, even in instances where it is clear that the claim was erroneous.

Established in the Realbuzz Group LTD v The Commissioners for HMRC tribunal case, HMRC must adhere to the deadline for discovery assessments.

While it can be challenging to make a client wait 12 months before making the most of their relief, there is another option.

The more confident you can be in the R&D tax relief claim’s validity, the less concerned the innovative business should be about ringfencing funds.

Seeking the guidance of an expert R&D tax consultant is vital in this and our team is on hand to assist at every stage of the process.

We have refined our approach to R&D tax relief claims over the years, building our experience by working closely with HMRC.

This approach has resulted in fewer than one per cent of our claims being subject to enquiry.

When we do defend R&D tax relief claims from enquiry, we are confident in being able to protect legitimate submissions.

Our enquiry support is robust enough to preserve the value of valid claims, with 99.7 per cent of our claims protected from enquiry.

To prevent the fear of enquiry holding you and your clients back, speak to our team today.

Adam Bointon

Adam Bointon is a Technical Director specialising in R&D Tax Credits for SMEs in manufacturing and software sectors. With over 15 years’ experience, he works closely with businesses to identify qualifying R&D activities and prepare clear, compliant claims. He combines technical expertise with a strong understanding of economics and finance to support successful outcomes. Adam also contributes to industry webinars and CPD sessions, sharing insights on R&D tax relief and HMRC requirements.