So it seems because banks used non-banking subsidiaries in the car finance practices (hidden pay-offs) that have led to a multi-billion compensation scheme, compensation payments will be tax deductible - very handy & a loophole of sorts as the banks themselves have been banned from off-setting such payments against tax since 2015.
Labour is being urged to close this loophole, but given its deregulatory push in financial services, it may not actually happen.