Local authorities have a general duty and several specific duties towards children and young people in need and to their families.
Section 17(1) of the Children Act 1989 imposes an overriding duty on all local authorities to safeguard and promote the welfare of children in need within their area and, so far as it is consistent with that duty, to promote the upbringing of such children by their families by providing a range and level of services appropriate to those children’s needs.
For more information on how advice providers, local authorities and their partners can work together to help prevent young people becoming homeless see Keeping families together: how to help.
A child is anyone under the age of 18.
Section 17(10) of the Children Act 1989 provides that children are in need if:
‘Family’, in relation to such a child, includes any person who has parental responsibility for the child and any other person with whom the child has been living.
In order to determine if a child is in need, the local authority must conduct an assessment of needs. A homeless child or young person under 18 is usually a child in need. 
For more information about the assessment of needs see Child in need assessment.
16 and 17 year olds assessed as in need become ‘looked after children’ entitled to social services’ support under section 20 of the Children Act 1989. They are also entitled to the care leaving package after the age of 18 and until their pathway plan comes to an end.
For more information about care leavers see Social services’ duties to care leavers.
Case law has established that the duties under section 17 of the Children Act 1989 are owed to children in need within a local authority’s area and is triggered when such children are physically present in the authority’s area. There is no need for the child to be habitually resident there. 
If a child in need is physically present in more than one area (for example, they live in one area but go to school in another) then both authorities have a general duty towards that child. When a child in need moves to another authority’s area, the new authority becomes responsible for meeting that child’s needs. 
However, in cases regarding Gypsies and Travellers, a local authority retains the power to provide section 20 services to a child in need assessed within its area even when the child moves to another area. 
If a child in need is in custody, the local authority’s duty does not cease and still applies to both the ‘home’ authority (the local authority originally responsible for that child) and the ‘host’ authority (the local authority in whose area the child is serving their sentence). 
In order to meet the general duty under section 17(1), local authorities can do anything which they consider necessary to safeguard and promote the welfare of children in need within their areas. This can include providing accommodation and assistance in cash. 
They must also fulfill the specific duties in Part 1 of Schedule 2 of the Children Act 1989. These include a duty to:
 R v Northavon District Council ex parte Smith  2 AC 402.
 R (on the application of Stewart) v Wandsworth LBC  EWHC 709 (Admin).
 R (on the application of Liverpool CC) v Hillingdon LBC  EWHC 1702 (Admin).
 R (on the application of J) v Worcester CC  EWCA Civ 1518.
 R (on the application of Howard League for Penal Reform) v Secretary of State for the Home Department  EWHC 2497 (Admin).
 s. 17(6) Children Act 1989.