Useful Links: The Main Manual: https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual INDEX: https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird80000 Application to Software CIRD 81960 https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird81960 Example of software claim that did not succeed: CIRD 81300 (definitions) https://www.gov.uk/hmrc-internal-manuals/corporate-intangibles-research-and-development-manual/cird81300