Merged scheme mayhem? Our end of year survival guide for accountants

The new RDEC and ERIS rules came into force in 2024 for claims starting on or after 1st April 2024, meaning that December 2025 will represent the first major tax deadline for claims made under the new regime.

Over the past year, we’ve published a series of blogs and resources to help advisers and claimants make sense of these changes and ensure their claims are accurate and compliant. In anticipation of December’s sudden uptick in merged scheme claims, we’ve gathered our key resources below and invite you to join our webinar next week.

New RDEC and ERIS

First things first – for a detailed overview of all aspects of claiming R&D tax relief under new RDEC or ERIS, your first stop is our Merged Scheme eBook . This gives you the foundation you need to get started under the updated rules.

Alongside this, we’d recommend reading up on when and how you might want to split a claim across the RDEC and ERIS schemes – we’ve written two blogs in this, one covering the why and how aspect , and the other explaining how the WhisperClaims app can help with this decision .

Finally, if your clients have longer accounting periods that straddle 1 April 2024, you will need to make sure you’re clear on how to handle transitional claims that may need to be split between the old and new regimes.

Overseas expenditure

Once you’ve got a good grounding, it’s time to look into the details of the overseas cost restrictions that form part of the new regime. Under the new schemes, subcontracted work that takes place outside of the UK is disallowed, as are EPW costs that are not subject to UK PAYE, with certain exemptions.

For a general overview of the measures, check out our blog about the overseas restrictions . We’ve also written in more specific detail about both overseas EPW costs and overseas subcontractor costs .

Subcontracting arrangements

The rules around claiming for subcontractors, or claiming for R&D performed on behalf of another entity are very different under the new RDEC and ERIS schemes, with Large Companies being able to claim for subcontracted costs for the first time, and more clarity of which entity can claim for the costs in the case of contracted out R&D.

For a general overview of the new rules and how they affected claims, check out our blog about subsidies and subcontracting . Alongside this, during this first year of claiming under the new schemes it’s important to understand the transitional rules that affect which entity can claim for subcontracted out R&D where companies have different year ends.

Northern Ireland ERIS

Finally, for any advisers working with companies registered in Northern Ireland, learning about the special rules for NI ERIS is essential. For NI companies that qualify for ERIS the overseas restrictions don’t apply but the claims are subject to the limits on de minimis aid, making this a complicated area of R&D tax relief.

We’ve written several blogs about NI ERIS:

The first explains the basics of the scheme and how to apply for it,

The second explores the differences between the new schemes and the calculations related to NI ERIS claims ,

The third looks at how grants affect all of the currently available R&D tax relief schemes.

Join our end of year webinar

Join us for our end of year survival webinar, on Tuesday 25 November 2025 at 12 noon, where we’ll recap the biggest legislative shifts, highlight the areas where advisers may still be getting caught out, and share practical tips to help you stay compliant, confident and ready for 2026.

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