If your child is on the SEN register it means they have a special educational need. A child or young person has SEN if they have a learning difficulty or disability which calls for special educational provision to be made for him or her. This often means needs that need support which are additional to and different from the mainstream. Where a child has high needs, this could make them eligible for an EHCP.
If you want to learn about what SEN support and EHCP numbers look like nationally, please follow:
https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/814244/SEN_2019_Text.docx.pdf