Express Authorithy

An express authority may be given to an agent orally or in writing.The most important factor is that the authority given has to be expressly stated in writing.The written authority may or may not be under seal.Hence,if the writing is ambiguous,for example- open to misinterpretation ,no liability can fall on the agent provided that interprets the ambiguity in a way in which it can reasonable be construed,even though it was not the way principal intended.