This paper reports findings from a postal questionnaire survey and in-depth interviews with UK funders of health-related research that explored whether, why and how they promote consumer involvement in research projects. Many UK funders of health-related research are adopting a policy of promoting consumer involvement in research projects. Telephone interviews revealed they have several reasons for doing so, and that they vary in the ways they encourage and support researchers to involve consumers. For some, descriptions of consumer involvement in a research proposal are important for project funding decisions. They recognized a need for flexibility when assessing consumer involvement in different contexts. We suggest that funders should continue to work to clarify what they consider to be the parameters of acceptability in terms of consumer involvement and ensure that 'flexible' criteria are fairly applied. Researchers should be aware of particular funders' views when applying for project funding.