Can my business make a claim under both the SME scheme and RDEC scheme?

In short, yes – as long as you are classified as an SME. The benefits of the RDEC scheme can be considered for SMEs who receive grant funding – e.g. a project specific grant application being submitted to a state aid body (such as Innovate UK). If the project is an eligible R&D project, the project must be claimed under the RDEC scheme. This applies only to the project that you received funding for.

For example, if you have 3 eligible projects and 1 of these projects received (state) grant funding, you can claim the other 2 projects under the SME scheme