The R&D PAYE/NIC Cap Explained!

This article is in two parts:

1. Understanding the CAP

2. What Happens When Your RDEC Claim Is Capped?

1. Understanding the CAP

The Cap is only relevant to companies that made a loss and want to get a payable tax credit under RDEC or ERIS.

Understanding this cap could be the difference between a meaningful cash injection now and a credit you can only use in future years.

The Formula

For accounting periods beginning on or after 1 April 2024, the payable credit is capped at:

£20,000 + (3 × Relevant PAYE & NIC)

This cap applies where a company is claiming a payable R&D credit (i.e. typically where it is loss-making). It does not restrict credits used to offset current-year Corporation Tax liabilities.

What Counts as “Relevant PAYE/NIC”?

Relevant staff PAYE/NIC costs includes:

• The company’s total PAYE and Class 1 National Insurance liabilities for the period (not just R&D staff)

• PAYE/NIC liabilities of connected companies, where they provide R&D workers as externally provided workers (EPWs) to the R&D project

The cap is based on PAYE/NIC liabilities actually incurred and paid — not gross payroll cost.

The “Low Headcount, High External Costs” Problem

Consider a biotech, hardware or software startup:

1. Two directors on modest salaries (or founders on no salary)

2. £200,000 of qualifying laboratory consumables or prototype materials or UK subcontractors

3. A payable R&D credit of £40,000

4. PAYE/NIC liabilities of £3,000

The cap would be:

£20,000 + (3 × £3,000) = £29,000

Result:

Only £29,000 can be received as a payable credit.

• The remaining £11,000 is carried forward as a non-payable R&D credit to offset future Corporation Tax.

• The claim value is not lost — but the immediate cashflow benefit is reduced.

The Exemption: When the Cap Does Not Apply

A company is exempt from the PAYE/NIC cap if both conditions below are met:

1️. IP Exemption Condition

The company must be creating, preparing to create, or actively managing intellectual property arising from the R&D. In practice, this means the company intends to own and exploit the IP — it is not merely conducting contract R&D for another party.

Crucially, this is interpreted as the company’s employees performing those activities. That means:

• They must be employees of the company

• They must be paid through PAYE

• They must be actively involved in the R&D or IP management

2️. Connected Party Condition

Payments to connected subcontractors and connected externally provided workers must not exceed 15% of total qualifying R&D expenditure.

There is no restriction on expenditure with unconnected third-party subcontractors but beware of the overseas contractor restrictions.

If both conditions are satisfied, the PAYE/NIC cap does not apply.

Three Practical Planning Points

1️. Review Director Remuneration

If your payable credit is close to the cap threshold, increasing salary (and therefore PAYE/NIC) can increase the cap by three times the additional PAYE/NIC paid. This must, of course, be commercially justifiable.

2️. Consider R&D Intensity

For R&D Intensive SMEs (ERIS), the cap still applies — and the impact can be greater because the potential payable credit is higher (c. 27%).

3️. Structure Subcontracting Carefully

Heavy use of unconnected third-party UK subcontractors will not breach the 15% connected party test.

However, connected party arrangements must be monitored closely.

For lean, innovation-led startups with low payroll and high project costs, modelling the cap early in the accounting period is essential. Waiting until the CT600 is prepared can lead to avoidable cashflow surprises.

2. What Happens When Your RDEC Claim Is Capped?

The introduction of the PAYE/NIC cap significantly changed the cashflow profile of UK R&D tax relief for startups and lean innovation-led businesses.

While the cap is designed to protect the system from abuse, it frequently affects legitimate, start-ups and high-growth companies with:

• Low headcount (few salaried staff)

• Modest PAYE/NIC liabilities

• Significant expenditure on consumables, materials, cloud computing or UK subcontractors

If your R&D claim has been restricted by the cap, the value is not lost — but accessing it may take time. 

The Lifecycle of a Capped Credit

This section explains what happens to any unused credits, under the merged R&D scheme (for accounting periods beginning on or after 1 April 2024), or ERIS, where the PAYE/NIC cap restricts the payable amount:

• The restricted portion becomes a carried-forward R&D credit.

• It is treated as a credit of the following accounting period.

• It then enters the normal statutory payment and set-off sequence.

Importantly, the cap does not reduce the underlying R&D credit calculation. It only restricts the amount that can be paid in cash to a loss-making company.

Year 2: What Happens Next?

In the following accounting period, the carried-forward credit is processed alongside any new R&D credit arising in that year.

Three key stages determine the outcome.

1️. Offset Against Corporation Tax

Before any payment is considered, the credit must first be used to settle any Corporation Tax liabilities for that period.

If the company has become profitable, the carried-forward credit will simply reduce the tax payable. In this scenario, the value is realised through lower tax rather than a cash repayment.

2. Recalculation of the PAYE/NIC Cap 

If the company remains loss-making and seeks a payable credit, the PAYE/NIC cap is recalculated for Year 2.

The total amount of R&D credit payable in that year — including both:

• The new Year 2 credit, and

• Any carried-forward credit from Year 1 must fall within: £20,000 + (3 × Relevant PAYE/NIC for Year 2)

If the company’s payroll remains low, the credit may be restricted again.

3️. The “Rolling Cap” Scenario

If PAYE/NIC liabilities remain modest, the restricted balance may simply carry forward again into Year 3.

This cycle can continue until one of the following occurs:

• Payroll increases sufficiently to expand the cap

• The company becomes profitable and offsets the credit against Corporation Tax

• The company ceases trading without sufficient profits or payroll to unlock the value

This is sometimes referred to as the “rolling cap” effect.

The Exemption: A Potential Exit Route

The PAYE/NIC cap does not apply in a period where the company meets the statutory exemption conditions.

Strategic Considerations

To avoid credits becoming trapped in a multi-year cycle, companies should monitor their cap position during the accounting period rather than discovering restrictions at CT600 stage.

Practical steps include:

• Reviewing PAYE/NIC headroom before year end

• Modelling how future payroll changes affect the cap

• Monitoring connected-party subcontractor spend

• Assessing eligibility for the exemption early

The earlier the modelling is done the more planning options are available.

Conclusion

The PAYE/NIC cap does not reduce the value of your R&D claim.

It limits how much can be paid in cash if you are loss-making.

For lean, high-growth companies, capped credits effectively become a deferred tax asset — recoverable when payroll increases, profitability arises, or the exemption conditions are met.

Understanding how the cap operates across accounting periods transforms it from an unexpected restriction into a manageable planning variable.

Need more information?

Visit Claiming RDEC Index Page for detailed guidance on many aspects of claiming Research & Development Expenditure Credits.

Get in touch for a free R&D discovery call and assessment or to ask a question.

Read HMRC Guidelines: Work out your Research & Development tax relief