  In the Standard Model (SM), flavour changing neutral current (FCNC) top
decays, possible at loop level only, are very strongly suppressed. Observation
of any such decay would be a direct signature of physics beyond the SM. Large
enhancements are possible in many "new physics" scenarios and the largest
enhancement is in most cases expected for the $t\rightarrow cH$ decay. A full
study for CLIC was based on the WHIZARD simulation of FCNC top decays within
the 2HDM(III) model. Beam polarization and beam-induced background were taken
into account. Top pair production events with the FCNC decay $t\rightarrow cH$
can be identified based on kinematic constrains and flavour tagging
information. Due to a large overlap in the kinematic space with standard top
pair events, the final signal selection-efficiency is small, at the 10% level.
Expected limits on $BR(t\rightarrow cH)\times BR(H\rightarrow b\bar{b})$ are
compared with earlier results based on parton level simulation.
