I'll call them and ask about this. I have my UCI from previous TRV application, that's how I was able to use the webform to send them my husband's new passport. I'm just worried about changing our address and maybe there's a conflict. This thing is making my anxiety worse.Nope, just a temporary number. Sigh. I think if you call them and they give you a temp number, you can change your address if it eases your worries!
But I'll give them a call and see if it's wise to change our address at this stage.