Enhanced R&D Intensive Support (ERIS) is available to loss-making SMEs whose relevant R&D expenditure is at least 30% of their total relevant expenditure, for accounting periods beginning on or after 1 April 2024. Both sides of the ratio aggregate connected companies, but payments between those companies come out of the total. This calculator checks the intensity condition; our ERIS guide covers the other conditions.
How the 30% test works
The ratio compares relevant R&D expenditure with total relevant expenditure for the period, aggregating connected companies on both sides. At or above 30%, a loss-making SME can claim ERIS: an additional 86% deduction and a 14.5% payable credit worth up to 26.97p per £1 of qualifying spend. Below 30%, the company claims under the merged scheme instead, unless the grace period applies.
One rule inside the aggregation catches groups out. Connected companies are counted on both sides — connection tested on any day in the period, so a subsidiary bought or sold part-way through the year still comes in — but a payment, or other transfer of value, to a connected company is excluded from total relevant expenditure. Leave intra-group recharges in the total and the denominator is inflated, which understates intensity and can put a qualifying company below the line on paper. Qualifying R&D expenditure still counts on the R&D side even where it takes that form, so the exclusion moves the ratio one way only: up.
The threshold is period-specific. The 30% test applies to accounting periods beginning on or after 1 April 2024; R&D-intensive support was introduced at 40% for expenditure from 1 April 2023, and periods on that older threshold can still be within their amendment window. If yours began before 1 April 2024, check what applied to it on our rates by year page — this calculator tests 30% only.
Intensity questions are rarely clean: connected companies, period lengths and cost boundaries all move the ratio. We will give you a straight answer on where you stand.
*For loss-making SMEs, in accounting periods beginning on or after 1 April 2024. Connected companies are aggregated on both sides, with payments between them excluded from the total. A one-year grace period can hold ERIS where intensity dips below 30%, but only where the company both met the condition in its most recent prior 12-month accounting period and obtained relief for it: eligibility without a claim does not bank the protection.
