Headteachers decide what's necessary
Keeping Children Safe in Education doesn't outline specific requirements for visitor protocols. Instead, it's up to schools to set processes for identifying and supervising visitors to ensure appropriate safeguarding measures are in place.
Headteachers will need to use their professional judgement to decide what's necessary. If you're in a maintained school, also check with your LA as they may set their own requirements.
For visitors attending in a professional capacity, you should check their ID and be assured that they've had the appropriate DBS check (you shouldn't ask to see their certificate if the visitor's employer has confirmed that its staff have had appropriate checks).
You shouldn't request DBS or barred list checks, or ask to see DBS certificates, for visitors such as children's relatives or other visitors attending a sports day.
You should set out your visitor