R&D tax credit calculator, 2026/27
Enter qualifying R&D spend to see an indicative benefit under the merged scheme or ERIS. Claims need a competent professional's judgement on what qualifies, treat this as a sizing exercise.
The r&d tax credit calculator runs on the rates and thresholds HMRC has published for the 2026/27 tax year, so the figures you see reflect the position your company is actually filing on rather than a historic set of bands. Change any input and the result recalculates immediately, with no sign-up and nothing sent anywhere.
If you are a director of a UK limited company, use it as a first look before a decision rather than as the decision itself. Merged scheme RDEC at 20% for accounting periods beginning on or after 1 April 2024; net benefit depends on your corporation tax rate. Real company positions bring in other income, reliefs, group structures and prior year adjustments that a single page of inputs cannot see, which is why the workings are written out below under corporation tax & limited company. Read those, then check the numbers against your own accounts, and speak to us if anything looks materially different from what you expected.
Last reviewed 12 September 2026 for the 2026/27 tax year. Reviewed by Waqas Sagar, Member of ICAEW, Fellow of ACCA, Fellow of AAT.
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Result, 2026/27
Estimated benefit after tax
Gross RDEC (20%)
Taxable above the line, so the net benefit is lower.Effective benefit
Claim window
Plus a claim notification requirement for new claimants.Illustration only, figures are based on the rates you have selected and the information entered. Please check your own position with us before acting.
Estimates for the 2026/27 tax year using published GOV.UK rates. Switch between 2026/27 and 2025/26 above.
What actually qualifies
The work must seek an advance in science or technology by resolving scientific or technological uncertainty that a competent professional in the field could not readily deduce. Building a website with standard tooling does not qualify; solving a genuine engineering problem, novel data architecture, performance at scale, new algorithms, can.
Qualifying costs typically include staff time, a share of employer NI and pension, externally provided workers, software and cloud and data costs used directly in the R&D, and consumables.
Process and evidence
Claims require an Additional Information Form submitted before or with the CT600, describing the projects, the uncertainties and the competent professional involved. New claimants may also need to notify HMRC within six months of the period end.
HMRC scrutiny has increased sharply. Contemporaneous notes, sprint records, technical decisions, failed approaches, are the difference between a defensible claim and a costly enquiry.
Timing and cash
The claim window is two years from the end of the accounting period. Payable credits take time to arrive, so plan runway around HMRC processing rather than the filing date.
What this means for your company
Treat the result as a planning figure for the 2026/27 tax year. If it changes what you were about to do, take a director's salary, a dividend, a large asset purchase or a filing decision, check it against your own accounts first. We can review the position with you and confirm the tax treatment before you commit.
Frequently asked questions
How much is R&D tax relief worth?
Under the merged scheme the 20% above-the-line credit is taxable, giving a net benefit of roughly 15 to 16% of qualifying spend. Loss-making R&D intensive SMEs under ERIS can receive around 27%.
Can a software company claim R&D relief?
Yes, where the work resolves genuine technological uncertainty. Routine development using established methods does not qualify, however commercially valuable it is.
How long does a claim take to pay out?
HMRC aims to process most claims within weeks of filing, but enquiries and compliance checks extend this considerably. Do not budget the cash as certain.
What records does an R&D claim need?
A project-by-project technical narrative, a breakdown of qualifying staff, subcontractor and consumable costs, and the additional information form HMRC now requires before the claim is valid. Claim notification may also be needed for first-time claimants.
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