The legislation is quite complex but broadly speaking the criteria for a company to claim under the SME scheme rather than the RDEC is that the number of full time employees is less than 500 and either a turnover of less than €100 m or balance sheet assets of less than €86 m.

The size is affected by whether the company is part of a group of companies or the shareholders have involvement in other companies. 

Despite the company meeting the SME criteria there may be projects which are ineligible for the SME scheme. This can occur when the company has received a grant that is notifiable state aid under EU regulations or where the company is subcontracted work from a company that is only able to claim under the RDEC.