In Information Commissioner vs Devon County Council & Dransfield  UKUT 440 (AAC), (28 January 2013) the Upper Tribunal found that the ordinary dictionary definition of the word vexatious is only of limited use. This is because the question of whether a request is vexatious ultimately depends upon the circumstances surrounding that request.
In further exploring the role played by circumstances, the Upper Tribunal placed particular emphasis on the issue of whether the request had adequate or proper justification. In doing so it approved a First-tier Tribunal’s conclusion from an earlier case that “vexatious” could be defined as the:
“….manifestly unjustified, inappropriate or improper use of a formal procedure.”
(paragraph 27 of the Upper Tribunal’s decision in Dransfield).
This clearly establishes that the concepts of “proportionality” and “justification” are central to any consideration of whether a request is vexatious.
On appeal, the Court of Appeal (Dransfield vs Information Commissioner and Devon County Council  EWCA Civ 454 (14 May 2015)), stressed that there was no challenge to the Upper Tribunal’s general guidance and the Court of Appeal cast no doubt upon it. The lead judgment, observed:
“…that the starting point is that vexatiousness primarily involves making a request which has no reasonable foundation, that is, no reasonable foundation for thinking that the information sought would be of value to the requester or to the public or any section of the public. …… The decision maker should consider all the relevant circumstances in order to reach a balanced conclusion as to whether a request is vexatious” (paragraph 68).
Therefore, we consider the key question you must ask yourself is whether the request is likely to cause a disproportionate or unjustified level of disruption, irritation or distress.
In some cases it will be easy to recognise that a request is vexatious. For example, the tone or content of the request might be so objectionable that it would be unreasonable to expect your authority to tolerate it, no matter how legitimate the purpose of the requester or substantial the value of the requested information.
Such as where threats have been made against employees, or offensive language used.
We do not expect you to make allowances for the value or purpose of the request under these kinds of circumstances.
Therefore, if you are dealing with a request which you believe to be clearly vexatious, you should not be afraid to reach a decision that section 14(1) applies.
However, in most cases, the question of whether section 14(1) applies is likely to be less clear-cut. You need to carefully consider whether there are sufficient grounds for refusing the request under section 14(1).
Before doing so though, we recommend that you consider whether there are any viable alternatives to dealing with the request under section 14. Some of the potential options are outlined in the ‘Are there alternative approaches?’ section later in this guidance.
Where alternative approaches are not practical, this guidance will help you carry out your assessment of whether the request is vexatious. To show this, we will refer to four broad themes developed by the Upper Tribunal in Dransfield.