What an Interception Warrant Can Make a Telecoms Operator Do

A warrant to intercept communications is not addressed to the operator. It is issued to an intelligence agency or police force, and the operator only meets it when someone serves it with a request for help. That small detail shapes everything about what an operator can be made to do.

This is general information about the Investigatory Powers Act 2016 (IPA), which is legislation, not guidance. Where I give an interpretation, I will say so.

The warrant authorises the agency, the operator just assists

Under Part 2, Chapter 1 of the IPA, the main warrant types are targeted interception, targeted examination and mutual assistance. The warrant names a target: a person, an organisation, a set of premises or a single operation. It is issued by a Secretary of State and, in the usual case, approved by a Judicial Commissioner before it takes effect. That is the "double lock".

The warrant itself makes interception lawful for the agency. The operator is then asked to implement it. The legislation puts a duty on the operator to take the steps the warrant requires of it, as notified by the person who serves it.

What "interception" actually covers

Interception means making the content of a communication available to someone other than the sender or recipient, while it is being transmitted. Content is the point. Who called whom, when and from where is communications data, and that sits under separate parts of the Act (authorisations and retention notices).

So a warrant can reach the body of an email or a call as it passes through the operator's systems. It does not, on its own, force the operator to hand over its billing records or to keep logs.

What the operator can be required to do

In practice the requests fall into a few buckets:

• Copy the target's communications and deliver them to the agency in an agreed format.
• Provide related communications data alongside the content, where the warrant covers it.
• Give technical help to make the interception work, such as access to the relevant part of the network.
• Keep quiet about it. Disclosing the existence or detail of a warrant is restricted, and unauthorised disclosure can be a criminal offence.

Operators can also be asked to work with the agency on how the interception is set up, since a warrant that cannot be technically delivered is not much use to anyone.

The limit: reasonable steps

The duty is to take steps that are reasonably practicable. The Act expects technical feasibility and cost to be weighed, and an operator who thinks a request is not reasonably practicable can raise that with the Secretary of State rather than just ignoring it. The duty also reaches operators outside the UK, but again only where it is reasonably practicable for them to comply.

If an operator simply refuses, the Secretary of State can seek to enforce the duty through civil proceedings, such as an injunction. That is the mechanism, not a criminal charge for failing to build a tap.

Quick detour: who pays?

Hang on, this bit is interesting. The Act requires the government to make arrangements for operators to receive a contribution towards costs of complying. The idea is that a small operator should not be put out of business by a warrant it did not ask for. How much anyone actually receives is a matter for those arrangements, not the statute.

Encryption: the operator can only hand over what it has

If a message is end-to-end encrypted and the operator holds no keys, a warrant does not conjure them up. My reading is that the operator can lawfully deliver the encrypted stream, and no more, unless it applied the protection itself and can remove it.

Removing protection the operator applied is the territory of a technical capability notice, a different instrument. Those can require an operator to maintain the ability to remove such protection. A warrant alone is a request to deliver what is reasonably available, not an obligation to redesign a service.

Duration, change and urgency

A targeted warrant lasts for a fixed period (six months at first) and can be renewed. It can be modified, for example to add a new phone number for the same target, and the operator receives the modified instructions. Urgent cases can be issued before judicial approval, with a Judicial Commissioner reviewing shortly afterwards, and the warrant lapsing if that review goes against it.

Oversight sits with the Investigatory Powers Commissioner, and the Investigatory Powers Tribunal handles complaints. Whether any particular request was properly made is a fact-specific question, and one an operator's lawyers would need to answer from the warrant itself.

The short version for an engineer

If you run a network and receive a warrant, the realistic position is this: the legal authority belongs to the agency, your duty is to take reasonable, practicable steps, and the limit is what you technically hold or can provide. What you cannot do is tell anyone, which is the part that tends to surprise people.

Primary text is on legislation.gov.uk, and the Investigatory Powers Commissioner's Office publishes oversight reports, both worth a read if you want the exact wording rather than my paraphrase.