The drone operator should have the permission of the CAA to carry out Commercial Operations; this is commonly known as a Permission for Commercial Operations (PfCO).
Each commercial drone operator who has been granted CAA permission will have a document from us granting the permission and setting out conditions for its use. You should ask the operator to show you his or her permission document and discuss how the work might be achieved within the conditions of the permission.
Please check the list of current holders of the CAA permission which is updated on a monthly basis.
The primary means of identifying an individual permission-holder is their permission document.
You should not rely solely on the claims of a potential operator within a website offering this service.