Deferred consideration: shares/securities: position before TCGA92 S138A - ESC D27
The treatment is different if the new debentures are QCBs. In this case the exchange of the notional security for the QCBs triggers the operation of TCGA92/S116. You compute the gain that would have arisen on a deemed disposal of the notional security. That gain is then released on a disposal of the QCB. For further details see CG58070+.