No, is the short answer.  Many people who attend voluntary police interviews do get charged, sometimes with serious offences.

The police may have a strong case against you, but have decided it is not necessary to arrest you.  As part of the police investigation they want to interview you and feel this can be done by calling you in for a voluntary interview.  If you don’t go to a voluntary interview, the police may decide they have to arrest you to carry out the interview because there is no other way it can be done.

The police codes of practice state:

2F An officer who believes that it is necessary to interview the person suspected of committing the offence must then consider whether their arrest is necessary in order to carry out the interview.  The officer is not required to interrogate the suspect to determine whether they will attend a police station voluntarily to be interviewed but they must consider whether the suspect’s voluntary attendance is a practicable alternative for carrying out the interview.  If it is, then arrest would not be necessary. Conversely, an officer who considers this option but is not satisfied that it is a practicable alternative, may have reasonable grounds for deciding that the arrest is necessary at the outset ‘on the street’.  Without such considerations, the officer would not be able to establish that arrest was necessary in order to interview.

To view the code, click here >

The code goes on to say:

When making arrangements for the person’s voluntary attendance, the officer should tell the person:

• that to properly investigate their suspected involvement in the offence they must be interviewed under caution at the police station, but in the circumstances their arrest for this purpose will not be necessary if they attend the police station voluntarily to be interviewed;

• that if they attend voluntarily, they will be entitled to free legal advice before, and to have a solicitor present at, the interview;

• that the date and time of the interview will take account of their circumstances and the needs of the investigation; and

• that if they do not agree to attend voluntarily at a time which meets the needs of the investigation, or having so agreed, fail to attend, or having attended, fail to remain for the interview to be completed, their arrest will be necessary to enable them to be interviewed.

2G When the person attends the police station voluntarily for interview by arrangement as in Note 2F above, their arrest on arrival at the station prior to interview would only be justified if:

• new information coming to light after the arrangements were made indicates that from that time, voluntary attendance ceased to be a practicable alternative and the person’s arrest became necessary; and

• it was not reasonably practicable for the person to be arrested before they attended the station.

If a person who attends the police station voluntarily to be interviewed decides to leave before the interview is complete, the police would at that point be entitled to consider whether their arrest was necessary to carry out the interview.