My ex partner owes me money for a holiday we went on, I paid for it on my credit card, the Invoices for the holiday are all in he's name. Now I'm left to pay the credit and he won't pay any money. Its £2,456. He's half. Can I take him to a small claims court and get him to pay? I'm a single mum with 2 kids (not he's kids)

First its not a good idea to piggyback your question on someone else's. This can lead to confusion. You should start a new thread. So I've moved your question to its own thread.

Second, do you have any proof that he agreed to pay his share?

You certainly can try to sue him, you might even win. A judge can certinaly infer that unmarried couples would agree to share expenses. But then you also have the difficulty of collecting, if you do win.