Help from the Information Commissioner
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What information does the IC need?
The IC will only be able to investigate your complaint if you give them copies of documents that describe what has happened. This will also help them give you the right advice. You should give them copies of relevant correspondence between you and the organisation you have a problem with. The IC will only contact an organisation about a possible data protection problem if you have raised the matter with them (or you give the IC a good reason why you could not do so). You should also send copies of relevant correspondence between you and any other body trying to solve the problem (for example, Citizens Advice, an industry regulator or an ombudsman).
You should only send documents that are directly relevant to your complaint. If you send too many or irrelevant documents, the IC may return them and ask you to sort them out and return only the relevant ones.
If you do need to send the IC a lot of documents, make sure you clearly mark the relevant parts. If you do not, they may return them and ask you to do this. It is important that you give the IC all the relevant documents when you first contact them. They will not normally consider extra information added later, which you could
have given them when you made your original complaint.