(25.11.2016) As Yui points out, the list of who has access to your records is laid out in Schedule 4 of the Act. „It‘s longer than you might imagine,“ he wrote.
Here‘s the full list:

– Metropolitan police force
– City of London police force
– Police forces maintained under section 2 of the Police Act 1996
– Police Service of Scotland
– Police Service of Northern Ireland
– British Transport Police
– Ministry of Defence Police
– Royal Navy Police
– Royal Military Police
– Royal Air Force Police
– Security Service
– Secret Intelligence Service
– GCHQ
– Ministry of Defence
– Department of Health
– Home Office
– Ministry of Justice
– National Crime Agency
– HM Revenue & Customs
– Department for Transport
– Department for Work and Pensions
– NHS trusts and foundation trusts in England that provide ambulance services
– Common Services Agency for the Scottish Health Service
– Competition and Markets Authority
– Criminal Cases Review Commission
– Department for Communities in Northern Ireland
– Department for the Economy in Northern Ireland
– Department of Justice in Northern Ireland
– Financial Conduct Authority
– Fire and rescue authorities under the Fire and Rescue Services Act 2004
– Food Standards Agency
– Food Standards Scotland
– Gambling Commission
– Gangmasters and Labour Abuse Authority
– Health and Safety Executive
– Independent Police Complaints Commissioner
– Information Commissioner
– NHS Business Services Authority
– Northern Ireland Ambulance Service Health and Social Care Trust
– Northern Ireland Fire and Rescue Service Board
– Northern Ireland Health and Social Care Regional Business Services Organisation
– Office of Communications
– Office of the Police Ombudsman for Northern Ireland
– Police Investigations and Review Commissioner
– Scottish Ambulance Service Board
– Scottish Criminal Cases Review Commission
– Serious Fraud Office
– Welsh Ambulance Services National Health Service Trust