I think you need to see a solicitor about this as soon as possible and make a Will appointing your parents (or other individuals) to be the guardian of your son in the event of your death, although of course you would have to speak to them beforehand to check that they are willing to accept such onerous responsibilities, and also have the funds, from your assets, to fund their education and upbringing. I am not sure, in law, whether your son's father would be able to override your wishes, but if he has had no contact with either you, or your son for seer years, I think it might be difficult, if it came to a legal battle, for him to take your son without any consultation. However, these are too important matters to leave things to chance or to happen by default and that is why you need to consult a solicitor, make a Will and get things legally sorted.