I can't say for the Spanish courts, but from the U.S. it was straight forward and no hassles. I had to provide a court attested document that I was the guardian of my step son and had no objections for him to move here. It was a one day process for me. Emirates is great in that aspect. Ask your recruiter and they will tell you exactly what you need from your home country. The problem with most courts is the objection part. The UAE is not a signer on the Hague Treaty and does not abide by it legally. Although, they mostly follow it, it's just not written legally that they do, which a lot of courts have huge issues with. The Hague treaty outlines child abduction laws for foreign countries. It's completely stupid though and BS. Statistically, the U.S. has more problems with Canada returning children than any other country in the world from divorced parents. And Canada is part of the Hague Treaty.