If your agency claims R&D tax credits on subcontractor costs, there is one rule you need to understand before you budget for the cash: the PAYE-NI cap. It limits the payable tax credit you can receive to a figure based on the PAYE and National Insurance your company actually paid. For agencies that lean heavily on freelancers and external developers while keeping a lean payroll, the cap can restrict a legitimate claim. The good news, which the older commentary online misses, is that the cap is far more generous than most founders fear, and the excess is not simply lost.
I have seen it bite. A three-founder studio in Shoreditch paid themselves mainly in dividends, taking token salaries below the National Insurance threshold, so their total PAYE and employer NI for the year came to roughly £1,500. They subcontracted a large platform build and their qualifying costs reached around £230,000. They expected about £37,000 back in cash. The cap held their payable credit to £24,500. The shortfall of roughly £12,700 was not written off, it carried forward, but the cash they had earmarked to make their first permanent hire did not arrive that year. They had not modelled the cap at all.
Let me explain exactly how the cap works under the current merged scheme, when it applies, and what you can do about it.
What Is the PAYE-NI Cap on R&D Claims?
The PAYE-NI cap exists to prevent abuse of the R&D system. HMRC had seen companies claim large payable credits built on subcontractor costs while paying almost no UK employment taxes themselves. The cap ties the cash you can extract to the employment taxes you generate.
Here is the rule in plain English. If you are claiming a payable (cash) R&D credit, the amount HMRC will pay you is capped at:
- £20,000, plus
- 300% of your company's total PAYE and Class 1 employer National Insurance for the accounting period.
That £20,000 fixed buffer is the part the outdated guides forget. It means a company with a modest payroll still has a meaningful floor, and the 300% multiple then scales the cap up quickly for anyone running a real team. An agency that paid £42,000 in combined PAYE and employer NI has a cap of £20,000 + (3 x £42,000) = £146,000, not £42,000. That distinction changes the entire picture.
The cap applies to the payable element of the credit, the cash HMRC sends you. It does not restrict the value of a credit used to reduce a corporation tax bill. And critically, under the merged scheme, any credit above the cap is not lost. It is carried forward and set against the company's tax liabilities in later periods. The cap changes the timing of your cash, not the total value of the relief.
The Scheme Has Changed: Merged R&D and ERIS
Before going further, it is worth being clear about which scheme you are in, because a lot of older material still quotes rates that no longer apply.
For accounting periods beginning on or after 1 April 2024, the separate SME and RDEC schemes were replaced by a single merged R&D expenditure credit scheme. It works like the old RDEC: you receive a taxable, above-the-line credit of 20% of your qualifying expenditure. For a loss-making company, that credit is paid out net of a notional tax deduction, leaving roughly 16.2% of qualifying spend for a small-profits-rate company, or 15% for a main-rate payer.
There is one exception. A loss-making SME whose R&D is at least 30% of its total expenditure can instead claim Enhanced R&D Intensive Support (ERIS). ERIS gives an extra 86% deduction and a payable credit of 14.5% of the surrenderable loss, worth up to about 27p per £1 of qualifying spend. That is materially more generous than the merged scheme, which is why the intensity test matters.
For context, the old SME scheme that these figures replaced offered an 86% enhanced deduction and a 10% payable credit for accounting periods beginning between 1 April 2023 and 31 March 2024. Before April 2023 the enhancement was 130% and the payable rate 14.5%. If a guide quotes 186% and 10% as the current position, it is describing a scheme that closed to new periods on 31 March 2024. The PAYE-NI cap formula itself, £20,000 plus 300%, has carried across into the merged and ERIS schemes unchanged.
Why Agencies Get Caught Out
Agencies have a structural exposure to this cap. Most digital, creative, and web design agencies run a small core of permanent staff alongside a much larger pool of freelancers and subcontractors. That is a perfectly normal operating model, but it creates a mismatch between where the qualifying spend sits and where the payroll sits.
Your qualifying R&D expenditure typically includes:
- Staff costs (salaries, employer NI, pension contributions)
- Payments to subcontractors (generally 65% of each payment to an unconnected subcontractor qualifies)
- Software and cloud or data costs used directly in the R&D (qualifying for periods beginning on or after 1 April 2023)
- Consumables and materials
If most of your R&D spend runs through subcontractors, your qualifying costs are high but your PAYE and NI can be low. The cap is built from your payroll, so the two figures can diverge sharply. The £20,000 + 300% formula gives you a lot of headroom, but it can still be breached when the payroll is genuinely tiny, which is exactly the position of a founder-only company paying dividends rather than salary.
The trap, then, is not the freelance-heavy agency with a proper team on the books. It is the company with almost no PAYE at all.
When the Cap Does Not Restrict You
The cap only limits the payable (cash) credit. If your agency is profitable and using the credit to reduce corporation tax, the restriction is not the binding constraint, because you are not asking HMRC to write you a cheque.
And even when you are loss-making and want the cash, the cap does not destroy value under the merged scheme. Suppose your payable credit works out at £45,000 but your cap is £35,000. You receive £35,000 now, and the remaining £10,000 is carried forward as an above-the-line credit to set against your company's tax liabilities in the next period. You have not lost it. You have deferred it. That is a very different outcome from the pre-2021 position that some founders still worry about.
The cap bites hardest, in cash-flow terms, for early-stage or founder-only companies that pay little or no salary. If the directors take dividends and keep PAYE near zero, the cap collapses towards its £20,000 floor, and a subcontractor-heavy claim can easily exceed that.
How the Calculation Works
Let me walk through the numbers so you can see the mechanics.
Agency profile: a 10-person web design agency in Bristol Harbourside. Turnover £650,000, loss-making after investing £300,000 in a proprietary CMS platform. Its accounting period begins after 1 April 2024, so it claims under the merged scheme.
Qualifying R&D costs:
- Staff costs (3 permanent developers): £120,000
- Subcontractor costs (5 freelancers): £150,000, of which 65% qualifies = £97,500
- Software licences: £12,000
- Total qualifying costs: £229,500
Merged R&D credit:
- Above-the-line credit at 20%: £229,500 x 20% = £45,900
- Net payable to a loss-making, small-profits-rate company after the 19% notional tax deduction: £45,900 x 0.81 = £37,179 (that is 16.2% of qualifying spend)
PAYE-NI cap:
- Total PAYE and Class 1 employer NI paid in the period: £41,000
- Cap: £20,000 + (3 x £41,000) = £143,000
Result: the £45,900 credit sits far below the £143,000 cap. There is no restriction. The agency receives its full £37,179. This is the common case: an agency with a real payroll clears the cap comfortably, because the 300% multiple on £41,000 alone gives £123,000 of headroom before the £20,000 buffer is even counted.
Now Strip Out the Payroll
Take the same £229,500 of qualifying costs, but assume the work is done through a single founder who draws dividends and a token salary, generating just £4,000 of PAYE and employer NI for the year.
- Merged credit: £229,500 x 20% = £45,900, net payable £37,179 as before
- Cap: £20,000 + (3 x £4,000) = £32,000
- Payable credit restricted to £32,000
- Excess carried forward: £37,179 - £32,000 = £5,179, set against future company tax liabilities