Thanks for asking the person at immigration. So little bit confused, sorry. When my ex wife and I divorced we went through a lawyer and both agreed and signed a divorce agreement which included joint custody and was notarized by the lawyers in the presence of witnesses. This was then submitted with the divorce at the amphur, of which they kept one copy. We both had to sign at the amphur that we agree to these terms. So it was my understanding that this legitamized the joint-custody.

@Stuart ********

Thank you and everyone else in the thread for the detailed response and for sending the requirements link. Just one last question, myself and my wife are divorced and have custody by mutual consent which was registered at the amphur when we got divorced. Is there a specific document I need to get to show this with my application?