What are the rules for paying maintenance/support for step children after separation?

A financial obligation to support a step child after the relationship has broken down is not automatic or dealt with in the same way as child maintenance in relation to a natural parent. Only standard cases are dealt with by the Child Maintenance Service (CMS) because their legal jurisdiction is limited to calculating maintenance for natural parents and their children. Step child maintenance is one of the few aspects of child support that the court still has the power to order.