All 12-15 year olds must book through NBS, because they will receive some additional information about the vaccination at the point of booking. The link below gives more information.
Information: Advice for children aged 12 to 15 years old and their parents or guardians. A set of COVID-19 vaccination resources for children and young people are available on GOV.UK in a variety of languages, Braille and Easy Read. These resources are to help children, young people and their parents or guardians make a decision about whether to get vaccinated.
PLEASE NOTE: There is a 12 week wait between 1st and 2nd doses. This is the gov. info page: https://www.nhs.uk/conditions/coronavirus-covid-19/coronavirus-vaccination/coronavirus-vaccine-for-children-aged-12-to-15/