In reply to girlclimber:
The problem is that "abroad" covers a large range of different legislations...
Just taking France for example: AFAIK you need to get a specific diploma (DEJEPS -
http://www.ffme.fr/formation/page/dejeps-escalade.html ) that allows you to take customers to a max altitude of 1500m. After that you need to be a mountain guide.
I know French instructors in the Pyrenees cross the border to Spain to take customers to climb there, but I have actually no idea if the instructors have got an official equivalence (somehow had their qualification stamped by Spanish officials or took a different Spanish qualification) or if there are local arrangements in place between countries.