“6…but the implementation of orders of this kind or indeed for any kind of division of costs in relation to specific issues can involve the parties and the costs judge in extensive further litigation in the course of the detailed assessment, during which the whole history of the action is scrutinised in order to determine which part of any expenditure related to which issue. In the present case, Master O'Hare was sensibly asked by the parties to make certain preliminary rulings as to the principles on which the division of the common costs should be approached. But I am told that this process has so far generated tens of thousands of pounds in additional costs and that the hearing of the detailed assessment has been allocated a further four days of court time. There is therefore every prospect that the length of time taken in the assessment of costs will exceed the length of the trial itself and add vastly to the costs of the litigation in general. These matters need, I think, to be borne firmly in mind by a trial judge who is asked to make a complicated order for costs. There is much to be said for the application of the general rule that costs should follow the event and for keeping to the simple formula of orders for a stated proportion of the costs or a stated amount of costs in cases where recognition of a limited degree of success by one or other party is called for.”
“72. From this review of authority I derive the following eight principles. (i) In commercial litigation where each party has claims and asserts that a balance is owing in its own favour, the party which ends up receiving payment should generally be characterised as the overall winner of the entire action. (ii) In considering how to exercise its discretion the court should take as its starting point the general rule that the successful party is entitled to an order for costs. (iii) The judge must then consider what departures are required from that starting point, having regard to all the circumstances of the case. (iv) Where the circumstances of the case require an issue-based costs order, that is what the judge should make. However, the judge should hesitate before doing so, because of the practical difficulties which this causes and because of the steer given by rule 44.3(7).(v) In many cases the judge can and should reflect the relative success of the parties on different issues by making a proportionate costs order… (viii) In assessing a proportionate costs order the judge should consider what costs are referable to each issue and what costs are common to several issues. It will often be reasonable for the overall winner to recover not only the costs specific to the issues which he has won but also the common costs.”