Definition
The CIRD Manual, short for Corporate Intangibles Research and Development Manual, is HMRC's published internal guidance on the corporate intangibles regime and the R&D tax reliefs. It covers the statutory definition of R&D, qualifying expenditure categories, the operation of the SME, RDEC, merged and ERIS schemes, subcontracting rules, compliance procedures and enquiry handling. Although not legally binding, the manual is the working reference used by HMRC officers and by most specialist advisers.
How HMRC defines it
The manual is published on GOV.UK at hmrc-internal-manuals/corporate-intangibles-research-and-development-manual. The R&D sections begin at CIRD81000. Key references include CIRD81300 for the meaning of R&D, CIRD82000 onwards for qualifying expenditure, CIRD89700 for RDEC, CIRD90100 for the merged scheme, and CIRD90700 for ERIS.
Practical example
An adviser preparing a claim for a software company references CIRD82500 for cloud and data costs, CIRD84000 for externally provided workers, and CIRD81300 for the underlying R&D definition. The manual provides the standard framework of references used in both the written claim narrative and in any subsequent correspondence with HMRC, allowing the position to be grounded in a citation trail that an HMRC officer will recognise.