Your ex-girlfriend will have to prove you are the father of this poor child before she can claim any money from you via the CSA. I say poor because she seems not to be a very responsible mother. You must demand a DNA test is done and refuse any payment until this is proven. Go to the Citizens Advice Bureau in your area and have them help you. It won't cost you anything and they will know of specialist solicitors who deal with these matters. If you are on a low income, you may well get legal aid, should you come to require legal help. You may well not be the father of this child, but if is proven that you are, then I am afraid you will have to pay up. You may also however be able to get a court order to allow you access to the child. It will be hard to make up these lost years, but if you are the father, at least try. I feel so sorry for both you and your present partner, as this is terribly unfair to both of you. But if you are strong, you will get through this and cope with whatever situation arises. Just hang in there and don't let it get between the two of you. It is obvious that your ex is seeking money as she has a lot of kids to feed and is probably struggling. If you are not the father, this is not your problem though and she should then leave you alone. Good luck, I do really hope this works out the way you wish it to.