Undisclosed agent
A charlatan, basically. The kind of knave who tells you, after having concluded a transaction with you, that he is in fact acting as agent for someone else, in doing so trying to claim he is not himself principally liable for the legal consequences of what he has done.
Don’t believe a word of it. An agent who doesn’t tell you he’s an agent is a principal. Well — effectively. The actual state of the law — which you can trace back as far as Lord Tenterden's rule from Thompson v Davenport in 1829 but finally formalised somewhat differently by Parke B in Heald v Kenworthy in 1855, suggests that there is an agency relationship, but the if it isn’t disclosed at all the counterparty can choose whether to sue the agent or (if its identity subsequently emerges) the principal.
Amwell J — a bear with little brain and even less persuasive impact on the courts of England and Wales — says this is all pap, and insists an agent who forgets to mention his agency at the time of striking a bargain is a principal (and a bounder). If you want authority for that statement, take yourself back to your very first contract law lecture, the one which outlined the essential ingredients of a bargain: offer, acceptance and consideration. The terms offered and accepted bind. If the “agent” made no mention of his “agency”, it is not a term of the contract, and he is yours, fully liable as principal, to throw into the snarling teeth of the common law of contract.
If the principal subsequently emerges, it would have to acknowledge the purported agency, and the counterparty accept it, to let the agent off the hook. That would be some kind of novation.
Undisclosed principal
This should be contrasted with the fellow who tells you in good time he’s an agent, all right, but just not for whom. More about that fellow can be found here. (in short, though, he too is effectively liable as principal (even if technically still an agent) until he’s told you who his client is).
See also
- Agent
- Principal
- Riskless principal
- Undisclosed agent (a.k.a. knave)
- Undisclosed principal