Estimate your R&D tax relief for 2026/27 under the merged RDEC scheme (20% expenditure credit) or Enhanced R&D Intensive Support (186% deduction, 14.5% payable credit).
UK staff costs, subcontractors, consumables, software and data used directly on qualifying R&D projects.
All company expenditure for the period. Used for the 30% R&D intensity test.
Sets your Corporation Tax rate: 19% up to £50,000, marginal relief to £250,000, then 25%.
Assumes all qualifying expenditure is UK-based. Overseas subcontractor and externally provided worker costs are restricted.
R&D tax relief was restructured 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, with one exception: loss-making SMEs that spend heavily on R&D can instead claim Enhanced R&D Intensive Support (ERIS). A company claims under one scheme for a given accounting period, not both.
The merged scheme gives a taxable expenditure credit at 20% of qualifying R&D costs. Because the credit is itself taxable, the net benefit depends on your Corporation Tax rate: roughly 15% of qualifying expenditure at the 25% main rate, and about 16.2% at the 19% small profits rate. It is available to companies of all sizes, profit-making or loss-making.
ERIS is open to loss-making SMEs whose qualifying R&D expenditure is at least 30% of total relevant expenditure. It allows an extra 86% deduction on qualifying costs on top of the 100% already in the accounts — a 186% total deduction — and a payable tax credit worth up to 14.5% of the surrenderable loss. That credit is not liable to Corporation Tax, which is why ERIS can be worth up to around 27p per £1 of qualifying spend.
A one-year grace period applies: if you met the intensity threshold and claimed in the previous period but fall below 30% in the current one, you may still be able to claim.
| Route | Mechanism | Indicative benefit |
|---|---|---|
| Merged RDEC — 25% CT | 20% taxable expenditure credit | ~15p per £1 |
| Merged RDEC — 19% CT | 20% taxable expenditure credit | ~16.2p per £1 |
| ERIS (loss-making, ≥30% intensity) | 186% deduction, 14.5% payable credit | up to ~27p per £1 |
It gives an indicative estimate from two figures — qualifying R&D expenditure and total relevant expenditure — plus your profit or loss position. It does not determine whether your projects meet the statutory definition of R&D, which is the part that actually decides a claim. It also does not apply the PAYE and NIC cap, group or linked-enterprise tests, the treatment of contracted-out R&D, or restrictions on overseas expenditure.
An R&D claim must generally be made within two years of the end of the period of account. Some companies must also submit a claim notification in advance. An Additional Information Form must reach HMRC before your Company Tax Return is processed — if the return is processed first, the claim is rejected.
Startups and SMEs carrying out qualifying development work, particularly software, engineering and product companies. If you are also modelling company profits and extraction, see our Limited Company Tax Calculator. For ongoing support, see our startup accountants.
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