Confirm the activity is R&D for tax purposes
HMRC expects projects that seek an advance in science or technology through resolution of scientific or technological uncertainty. Routine configuration and cosmetic change usually sit outside the definition.
Assemble qualifying expenditure carefully
Staffing costs, externally provided workers, consumable materials, software, and subcontracted R&D each have specific rules. Scheme choice and company size affect the calculation path; treat published rates as of the Index parameters date.
Use estimates to prioritize, not to file
An Index estimate helps finance decide whether to engage support. Filing still requires a compliant claim narrative, correct CT computation, and awareness of additional information requirements HMRC publishes for R&D claims.
Primary source
Read HMRC Corporation Tax R&D relief guidance, then the Credit Index UK standards page, before you circulate a board-level figure.