TED helps staff keep questions open, so the child gives their own account in their own words. Typical prompts are "Tell me what happened", "Explain what you mean by..." and "Describe where you were". The opposite is a leading question, such as one that names a person or suggests an answer.
TED isn't in KCSIE or Working Together. It appears in local authority and school training. Devon County Council's guidance for schools, for example, refers to "the TED approach" and notes that it needs good language skills, so children with communication needs may need other support, such as visual aids that don't lead.
The principles behind it are in KCSIE 2026. Staff should know what to do when a child tells them about abuse, never promise secrecy, and reassure the child they are being taken seriously (paragraphs 14 and 15). The adult's role is to listen and pass the concern to the DSL, not to investigate. If the police later interview the child, they follow the Ministry of Justice's Achieving best evidence guidance, and early questioning by staff can affect that.
Local practice differs on follow-up questions. Some areas suggest "what, where, when, who" questions only to clarify; others advise against them. Follow your school's child protection policy and your local partnership's training.