Intention of the parties
If it is clear from the dealings between the parties that A is intended to have right against T, then this will be given effect. The cases mainly deal with the situation where A is liable to T on this basis, as in The Swan (1968), but there is no reason to doubt that A in such a situation would also have been entitled to sue if, for example, the repair work had been unsatisfactory
Custom or trade usage may, in some cases, mean that A is able to sue on a contract. The courts will give effect to this, unless a clear contrary intention has been expressed.
As discussed above, where P is undisclosed, T may have a right of action against both A and P. The requirements of mutuality mean that the agent may also be able to sue, if P does not.
Agent is principal
The agent who, while purporting to act for a principal, in fact, acts personally, will be entitled to enforce the contract with T. The authority for this is Schmaltz v Avery (1851), a case which has been the subject of criticism, but which remains good law. The plaintiff had signed a charter party ‘as agents of the freighter’. They, subsequently, tried to sue on the charter, as P the defendants objected that their status as ‘agents’ precluded this. The court rejected this argument.
This will, generally, arise in relation to pre-incorporation contracts. The case of Newborn v Semisolid (1953) has been discussed. The agent in that case was not allowed to sue in his own name because the way in which the contract had been signed was inconsistent with this. The change in the law, now contained in of the Companies Act 1985, which made agents personally liable on such contracts, does not specifically deal with their power to enforce. It seems likely, however, that the provision would be interpreted as giving such a power. The continued authority of Newborn v Semisolid (1953) must, therefore, be doubtful, though it has never specifically been overruled.
It was important that the court did not feel that the defendant was in any way prejudiced by the plaintiff’s action. If the identity of the principal were significant, or if it were clear that T would not be prepared to contract with A as P, then the position would be different, as it is where an undisclosed principal wishes to enforce a contract.