My multi pilot IR has never expired, however i have not flown under single pilot IR for a while. Under JAR that would not be an issue but the UK CAA consider the SPA IR and the MPA IR to be two different rating.
So i am assuming this is a renewal of my SPA IR even if my MPA IR is still valid. This require a test in the aircraft.
Reading EASA, there doesn't sem to be a difference now between the MPA and SPA IR?