how can i make a British citizen pay child support to me when I and my child live in America?

Answer 1

Check out this site. It may be of some help.

CHILD SUPPORT ENFORCEMENT - Country Specific United Kingdom

Link Below!

Answer 2

You simply need to open a case with your local child support agency. America has reciprocity with the UK, so they will be able to work with British agency in enforcing a child support order. However, don't expect it to be a speedy process, I've had dealings with international cases and it is typically a slow process.