Part 2: Lawful interception of communications Chapter 1: Interception and examination with a warrant Section 43: Duty of operators to assist with implementation
This section provides that a telecommunications or postal operator served with a targeted interception warrant or a mutual assistance warrant is required to take steps to give effect to it. The obligation applies whether or not the operator is in the UK. However, the operator is not required to take any steps that it is not reasonably practicable for the operator to take. Subsection (5) makes clear that in considering what is reasonable, any requirements or restrictions under the laws of the country in which an operator is based must be taken into account. Subsection (6) provides that, where a technical capability notice under Part 9 has been given to the operator, the requirements placed on the operator are relevant to the consideration of what is reasonable.
	Subsection (7) sets out the offence for knowingly failing to comply with the obligation to give effect to an interception warrant. The duty to comply with a warrant is enforceable against a person (whether or not they are in the UK) by civil proceedings brought by the Secretary of State.