Joint and several liability
In contract, it arises when two or more persons in the same contract jointly promise to do the same thing, but also separately promise to do the same thing. For example, if A and B promise jointly and severally to pay £100 to C, then they are together under an obligation to pay £100 to C, but also individually they are under an obligation to pay the money to C. Performance by A or B discharges the obligation. In such a case, C is entitled to £100 in total and it can enforce the obligation in full against A or B or both. If C sues A and not B, it is open to A to claim a contribution from B.
In tort, joint and several liability may arise where A and B act independently to cause C the same damage (for these purposes, A could be a contract-breaker and B a tortfeasor). In such a case, C is entitled to sue all or any of them for the full amount of its loss. If C sues A but not B, it is open to A to seek a contribution from B, in respect of its relative responsibility. For more information, see Practice note, Joint, several and joint and several liability ( www.practicallaw.com/1-200-4741) .