We are guided at all times by the SEND code of practice: 0 to 25 years. 

"In considering whether an EHC needs assessment is necessary, the local authority should consider whether there is evidence that despite the early years provider, school or post-16 institution having taken relevant and purposeful action to identify, assess and meet the special educational needs of the child or young person, the child or young person has not made expected progress. To inform their decision the local authority will need to take into account a wide range of evidence, and should pay particular attention to:

• evidence of the child or young person’s academic attainment (or developmental milestones in younger children) and rate of progress
• information about the nature, extent and context of the child or young person’s SEN
• evidence of the action already being taken by the early years provider, school or post-16 institution to meet the child or young person’s SEN
• evidence that where progress has been made, it has only been as the result of much additional intervention and support over and above that
  which is usually provided
• evidence of the child or young person’s physical, emotional and social development and health needs, drawing on relevant evidence from clinicians and other health professionals and what has been done to meet these by other agencies, and
• where a young person is aged over 18, the local authority must consider whether the young person requires additional time, in comparison to the majority of others of the same age who do not have special educational needs, to complete their education or training. Remaining in formal education or training should help young people to achieve education and training outcomes, building on what they have learned before and preparing them for adult life" (Special educational needs and disability code of practice: 0 to 25 years, DoE & DoH, January 2015)

Our guidance contains information for educational settings, parent/carers and young people about how to request an EHC needs assessment, as well as outlining what needs to be included with your request.