'at my own expense'...
Hi, Could anyone please tell me if there is any informal way of saying this, especially in BrE?
Mehrgan.
If you're just talking about money you could say: "out of my own pocket".
There are plenty of informal phrases meaning that you were the one who had to pay, but 'at my own expense' could be nothing to do with money: "I like to tell jokes at my own expense". As susie says, more context is needed.
not a teacher