When advising an elderly or vulnerable individual on any aspect of litigation, it is very important to consider whether they have capacity to litigate. A party to litigation who lacks the capacity to conduct the proceedings is a person lacking capacity within the definition of the Mental Capacity Act 2005 (MCA 2005) and, since 1 October 2007, is known as a 'protected party'. Where a claim is made by or on behalf of a protected party or against a protected party, no settlement, compromise or payment and no acceptance of money paid into court is valid, so far as it relates to the claim by, on behalf of or against that person, without the approval of the court. Principles of capacity under MCA 2005 Before considering the specific rules and case law relating to capacity to litigate, it is worth considering the relevant general principles of capacity under MCA 2005: • MCA 2005, s 1(2) states that a person is assumed to have capacity unless it is established that they lack capacity. There is therefore a burden of proof