S.243(1)(b) of Companies Act 2014 specifically addresses this issue.
Any guarantee provided by any company within the group for another company within the group is permitted (assuming the definition of a subsidiary company has been met as stated in S.7 CA 2014). The definition of a subsidiary is contained in S.7 CA 2014 and defines when a subsidiary relationship exists – a subsidiary includes instances where a golden share is held which gives the right to the holder to control the composition of the board). One exclusion is where a guarantee is provided in connection with the acquisition of a company’s own shares (i.e. where financial assistance is given for the purchase of a company’s own shares even if they are in a group). This is prohibited under Section 82 of CA 2014 unless it is approved by way of a summary approval procedure under Section 203 of Companies Act 2014.