Part 6: Bulk warrants Chapter 1: Bulk interception warrants Section 145: Modification of warrants
This section sets out the modifications which may be made to a bulk interception warrant.
	The only modifications that may be made are adding, varying or removing any operational purpose specified in the warrant, or providing that the warrant no longer provides for the interception of communications covered by the warrant or the obtaining of secondary data from those communications.
	Subsections (4) and (5) require that any modification to add or vary an operational purpose (a major modification) must be made by the Secretary of State and, except in urgent cases, approved by a Judicial Commissioner.
	Subsection (6) provides that a senior official, acting on behalf of the Secretary of State, may make a modification to remove an operational purpose or to cancel the interception of communications (a minor modification). Subsection (12) provides that where a warrant is modified to cancel the interception of communications it remains a bulk interception warrant. Where a minor modification is made by a senior official, the Secretary of State must be personally notified of the modification, as well as the reasons for making it.
	Subsection (8) places an obligation on the Secretary of State, or senior official acting on their behalf, to remove an operational purpose where selection for examination of content or secondary data for that purpose is no longer necessary.
	Subsection (10) provides that where there is a need to make a major modification, but it is not reasonably practicable for the Secretary of State to sign the instrument making the modification, it can be signed by a senior official acting on behalf of the Secretary of State, but the modification must be personally authorised by the Secretary of State. Such a modification is not an urgent modification and must still be approved by a Judicial Commissioner before taking effect.