The Department for Transport (DfT) has changed its online advice, and now says that minibuses cannot be driven for profit without an O-Licence, and that drivers cannot be paid (except for out of pocket expenses) when being driven on a Section 19 Permit or similar. The changes to its website were made on 30 March and 2 April. Details are at https://www.gov.uk/driving-a-minibus and www.gov.uk/vehicles-can-drive