If your school can't get in touch with parents/carers
Schools must notify parents/carers of suspensions or permanent exclusions 'without delay' (see paragraph 63 of the suspensions and permanent exclusions guidance, from September 2023).
Schools should notify parents/carers in person or by phone in the first instance, as this will allow parents/carers to ask questions or raise concerns (see paragraph 73). Your school should maintain correct and up-to-date phone numbers for parents/carers so the headteacher is able to do this.
Sometimes parents/carers can't be reached despite the school's best efforts
Remember, your school is still responsible for the pupil while they're on site and sending them home without a parent or carer accompanying them could be dangerous. Your headteacher must exercise their legal duty of care when deciding whether to send a pupil home (see paragraph 3).
Remove the pupil from the classroom