Why do some UK school buses display this sign and other don't?

[JetBlast]

I am wondering why some school buses in the UK display this sign and others don't please? Maybe some local authorities don't make it compulsory?
(Image below shows the black-on-yellow school bus sign depicting two children)

Thanks

 

[M803UYA]

I am wondering why some school buses in the UK display this sign and others don't please? Maybe some local authorities don't make it compulsory?

Thanks

Depends on the type of service. If the school contract operates as a registered local bus service, the signage is not required to be displayed. Doing so potentially invalidates the fuel duty rebate (BSOG) claim. If it's a closed door contract (one not open to the general public) then the signage needs to be displayed front and rear.

 

[High Dyke]

As above. The requirement to display the sign comes under The Road Vehicles Lighting (Amendment) Regulations 1994.