Under normal circumstances, child maintenance is dealt with by the Child Support Agency (CSA). They will work out how much the non-resident parent should pay to the resident parent.
Where the non-resident parent lives abroad, unless they are a UK registered company or government employee, the CSA will not handle the maintenance payments. If an agreement cannot be reached between the two parents over payments in these cases, then it will be necessary to make an application to the court for a Child Maintenance Order.
The court may also become engaged in child maintenance issues under other circumstances, including where the parent liable for the payment is particularly wealthy; if there are educational expenses to be covered or once the child reaches the age of 17 and is therefore no longer under the scope of the CSA.