My wife and I are both Indonesian nationals, currently living in the UK on a Tier 2 Visa.
We had a baby born in the UK recently. He has a birth certificate and no passport. How do we get him a permission to stay in the UK?
Being born in the UK is generally not enough to satisfy the UK citizenship requirements. From the information you have provided, your son will likely not qualify. You will need to apply for a tier 2 dependent visa for your son. The application will require your son to have a valid passport. My understanding of the UKBA rules are that you do not need to apply immediately for the dependent visa. However, your son will need the dependent visa to renter the UK if he has to leave the country for an emergency.