R&D tax relief pre-notification: who needs it and when is the deadline?

If you're planning to claim R&D tax relief, you may need to notify HMRC before submitting your claim.

This requirement, known as the R&D pre-claim notification, applies in certain circumstances. Missing the deadline could prevent your business from claiming R&D tax relief for the relevant accounting period, making it an important consideration when planning a claim.

Key takeaways

• Some businesses must notify HMRC before submitting an R&D tax relief claim.
• Whether pre-claim notification is required depends on your company's claim history and circumstances relating to R&D claims
• Where notification is required, the deadline is generally six months after the end of the relevant accounting period.
• Missing the deadline could mean you are unable to make a claim for that period.
• Reviewing your position early can help avoid unexpected compliance issues later in the claims process.

What is R&D tax relief pre-notification?

R&D pre-notification is an administrative requirement introduced by HMRC for certain businesses intending to claim R&D tax relief.

It is not the claim itself. Instead, it informs HMRC that a company intends to submit an R&D tax relief claim at a later date.

Where notification is required but not submitted before the deadline, HMRC will reject a subsequent claim for that accounting period as invalid There is no legislative recourse or appeals process.

A quick pre-notification checklist

You may need to notify HMRC before submitting an R&D tax relief claim if:

This is your first R&D tax relief claim.

You have not submitted a recent valid R&D claim.

A previous claim has been rejected, removed or disallowed.

A previous claim was submitted through an amended Corporation Tax return in circumstances that do not satisfy HMRC's notification rules.

If you're unsure whether any of these circumstances apply, it is important to review your position well before the notification deadline.

Do I need to pre-notify HMRC?

Whether pre-notification is required depends on your company's individual circumstances and claim history.

You may need to submit an R&D pre-notification if:

• You have not made a valid R&D claim within HMRC's relevant claim history window.
• A previous R&D claim has been rejected, removed or disallowed by HMRC.
• The only claim within the relevant window falls within certain amended Corporation Tax return circumstances.

In many cases, companies that have made a recent valid R&D tax relief claim may not need to submit a pre-notification. However, first-time claimants, businesses returning to the scheme after a gap, and companies whose previous claims have been amended, challenged or removed should review their position carefully.

Because the rules can be complex, it is important to review your claim history before starting a new claim.

Who is most likely to need R&D pre-notification?

While each company should be assessed on its own circumstances, pre-notification is more commonly required where there is limited recent claim history or uncertainty over whether previous claims qualify.

This may include:

• First-time R&D tax relief claimants
• Businesses that have not claimed R&D tax relief recently
• Companies that claim intermittently rather than every year
• Businesses whose previous claims may not qualify as valid claims for notification purposes
• Companies with claims that have subsequently been removed or disallowed by HMRC

How to determine whether pre-notification is required

The best starting point is to review your recent claim history.

For each of the previous accounting periods, consider:

• The accounting period end date
• Whether an R&D claim was submitted
• When the Corporation Tax return was filed
• Whether the claim formed part of the original return or an amendment
• Whether HMRC subsequently challenged, removed or disallowed the claim

Reviewing this information early can help identify whether notification may be required and avoid unnecessary delays later in the process.

How is R&D pre-notification submitted?

HMRC requires businesses to submit a pre-notification claim (PCN) form online.

The notification generally includes basic information about the company and the accounting period for which a claim may be made.

Pre-notification does not replace the R&D tax relief claim itself; this must still be prepared and submitted within the corporation tax deadlines.

Common mistakes to avoid

Common issues include:

• Assuming a previous claim automatically removes the need to notify HMRC
• Leaving R&D discussions until year-end compliance work begins, as this may be too late
• Overlooking notification requirements because claims are made infrequently
• Failing to check whether previous claims were submitted as amendments

What is the R&D pre-notification deadline?

Where notification is required, it must generally be submitted within six months of the end of the relevant accounting period.

When does the six-month deadline start?

The deadline is generally calculated from the end of the accounting period for which the company intends to claim R&D tax relief.

For example, a company with a 31 March accounting period end would generally have until 30 September to submit a required notification.

Example deadlines

These examples are illustrative only. The deadline will depend on your company's accounting period and circumstances.

What happens if you miss the deadline?

Missing a notification deadline can have significant consequences.

Where notification is required and not submitted on time, a company may be unable to claim R&D tax relief for that accounting period. HMRC provides limited options once the deadline has passed.

For that reason, businesses considering a claim should review their position as early as possible rather than waiting until the full claim is ready to submit.

What if an earlier claim is under enquiry?

If an earlier R&D claim is currently under HMRC enquiry, it may be worth considering whether a protective pre-notification is appropriate.

If a claim is subsequently removed and no notification has been submitted, the relevant deadline may already have passed. Taking advice at an early stage can help businesses understand the options available and avoid unintended consequences.