Renew London is not registered with the ICO, nor is any company with a similar name at their postcode [1].
So either they believe that they're exempt, or that it's under a different name.
The ICO has a self-assessment tool [2] to work out whether an organisation is required to register. I'd suggest that the big question is: "Are you processing personal information?". The definition is:
‘Processing’ means doing any of the following with the information:
obtaining it
recording it
storing it
updating it
sharing it
‘Personal information’ means any detail about a living individual that can be used on its own, or with other data, to identify them.So based on that, they're processing personal information and are legally required to register and comply. The ICO is not seen as an overly strong regulator, but they might be convinced to investigate after the inevitable headlines in the papers.
[1] http://www.ico.org.uk/esdwebpages/search. Postcode is E1 6DY from their website in the press release [2] http://www.ico.org.uk/for_organisations/data_protection/regi...