There are a number of approaches that you could take, but reference to HMRC’s eligibility criteria and guidelines is essential. This turns the conversation from you vs the client, to both of you vs HMRC.
Reminding them of the consequences of submitting a claim without a clear case for eligibility may also help. It isn’t just repayment they need to worry about. An HMRC enquiry takes a lot of time to deal with, and there’s always the possibility of penalties if HMRC feels that they’re warranted.
Our free eligibility checklist is a useful tool for guiding these difficult conversations. You can use it to walk through the core aspects of eligibility in a structured way and demonstrate to clients what it takes to build a solid claim.