If 123-Reg is possibly going to go bust I would strongly urge anyone using them to move away now.
Many years ago I had my main domain with a company that suddenly stopped responding to all attempts at contact. In despair I eventually contacted Nominet, the .uk registrar, and went through a slow and anxiety-making process to get my domain released.
I know they get a lot of flak but Nominet were very helpful, and they had to make absolutely sure that I really did own the domain before they could transfer it. Thankfully it was eventually sorted. Phew!
If anyone is looking for alternatives I would highly recommend Zen. (I have no connections with Zen other than as a happy customer.)