Capacity in English law refers to the ability of a contracting party to enter into legally binding relations. If a party does not have the capacity to do so, then subsequent contracts may be invalid; however, in the interests of certainty, there is a prima facie presumption that both parties hold the capacity to contract. Those who contract without a full knowledge of the relevant subject matter, or those who are illiterate or unfamiliar with the English language, will not often be released from their bargains.