Request for substitution process

[TheCyclingProgrammer]

There's only one reply needed here:

"It's none of your business"

Ask your client if they'll provide you with details of their directors remuneration process and see how far you get with that.

This is incredibly short-sighted advice.

A strong right of substitution clause will pretty much put your role outside IR35. A client asking for details of your substitution process shows that they are willing to take your right of substitution seriously. Having an agreed substitution procedure in place that the client has both enquired about and explicitly agreed to would make it very difficult for HMRC to claim it is a sham. I can't think of any reason why you wouldn't be willing to both document and agree this process with your client.