I have shared residence of my DC in the UK with my STBXH and for the most part our relationship is very amicable, and we've been able to put DC's needs above our own issues with the split.
However, I have reason to believe that STBXH is thinking about moving back to his home country, although most likely in a 'I'd like to if I could' not a 'making plans' way as he knows I'd never agree to DC moving to a different country.
Tbh, I'm probably worrying over nothing but don't like to leave anything to chance where my DC is concerned. STBXH is capable of doing some pretty selfish and stupid things but I don't think he'd be that stupid.
I have DC's passport and birth certificate. Can he apply for a replacement passport without them? Anything else I need to make sure we're protected?
As mentioned, I have no reason to think he might try go with DC without my permission but I'd rather be careful.