The Home Office has issued a new code of practice that relates to the powers and duties conferred or imposed under the Regulation  of Investigatory Powers Act 2000 Part One, Chapter Two. It provides guidance on the procedures to be followed when an acquisition of communications data takes place under those provisions. This version of the code replaces all previous versions of the code.

https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/426248/Acquisition_and_Disclosure_of_ Communications_Data_Code_of_Practice_March_2015.pdf