The simple answer is no, but there are potential consequences in certain circumstances.

When can they ask?

It is arguable that the police could ask you whenever they wanted for your PIN, you can always say no. The critical issue is whether they can take further action if you say no.

When can they take further action?

Section 49 of the Regulation of Investigatory Powers Act 2000 contains the relevant power.

If your phone has been seized, or in circumstances where they have the power to inspect it, the police can give you notice that they require you to provide the PIN or “encryption key” to allow them access. The same applies to other devices such as computers.

Written permission must be obtained from a Judge or a District Judge for the giving of a notice under section 49, this then provides “appropriate permission”.

The person with “appropriate permission” requesting the information must believe, on reasonable grounds:

(1)    that the key or PIN is in your possession;

(2)    that the notice is necessary for the grounds listed below, or it is necessary for the purpose of securing the effective exercise or proper performance by any public authority of any statutory power or duty

(3)    the notice is proportionate; and

(4)    that it is not reasonably practicable for the person to obtain possession of the protected information without the giving of a notice.

A notice is necessary (as in (2) above) if it is necessary:

(1)    in the interests of national security;

(2)    for the purpose of preventing or detecting crime or

(3)    it is in the interests of the economic well-being of the UK.

What would “notice” be?

A notice has to be in writing (or otherwise recorded), set out the protected information to which it relates, set out the grounds for requiring it (as above), specify the office, rank or position of the person giving it, specify the office, rank or position of the person granting permission for it to be given, specify the time by which the notice is to be complied with, and finally, what disclosure is required and how it is to be provided.

What is concerning is that people are very often given documents that leave the impression that giving the passcode is compulsory, when in fact they are mere requests not authorised by any higher body – you should always seek the advice of a solicitor before complying with any request.

What if I do not know the PIN or still don’t want to give it?

If you do not comply with a properly given notice, you can be prosecuted. If you know the information required and refuse to provide it, you can be sentenced to a maximum of 2 years imprisonment or 5 years imprisonment for an offence involving national security or child indecency.

If you genuinely do not know the information you can put this forward as a defence to the offence.

The legislation says that a person will be taken as not being in possession of a key (or PIN) if “sufficient evidence of that fact is adduced to raise an issue with respect to it and the contrary is not proved beyond a reasonable doubt”. 

What sentences have been given? 

Andrew Garner failed to comply with a notice, he said that he had forgotten the PIN but was found guilty and given eighteen months imprisonment. Tajan Spaulding pleaded guilty after refusing to provide the PIN for his iPhones and was given eight months imprisonment. Stephen Nicholson was given 14 months imprisonment for failing to provide his Facebook password to the police during the investigation into the murder of Lucy McHugh.