CG42390 explains when the exit charge under TCGA92/S185 may be postponed where a company migrated before 1 January 2020. The whole or part of the postponed gain becomes a chargeable gain of the principal company
•if a relevant asset is disposed of within six years of the relevant time and a gain would have accrued on the deemed disposal of the relevant asset at the relevant time, or
•if at any time either
•the principal company disposes of any of the ordinary shares in the subsidiary and after the disposal the subsidiary is not a 75 per cent subsidiary (whether or not it was before), or
•the principal company ceases to be resident in the UK.