This Practice Note considers the legal capacity (or incapacity) of parties to enter into arbitration agreements and to participate in arbitration proceedings. The Practice Note covers the consequences of incapacity, applicable law to determine capacity (with English and Swiss law by way of example), a state’s capacity under public international law and the impact of insolvency on capacity. The Practice Note also gives guidance on capacity issues to consider when entering into an arbitration agreement. It also links to content on the authority of signatories to contracts.