Can I reuse a previous R&D tax credit claim?

The short answer is no. If you have previously submitted an R&D tax credit claim, then you will not be able to resubmit a claim for a new case. 

HMRC does accept that R&D projects (especially the more complex ones) can last multiple years, and in these cases it is important to detail the different stages of the project along with the different expenditure from each year.

So while the project may be the same, the content of the accompanying documents showcase the progress in your claim.

For prolonged research and development projects, you may refer to a previous claim as a frame of reference, to ensure that there is no overlap between the separate claims.