The Home Office collects and processes personal data to fulfil its legal and official functions. We will only collect and process personal data where we have a legal basis to do so and it is necessary and proportionate.
The Home Office may share information with other organisations, but only where the information needs to be shared and there is a legal basis for doing so. Further detail on this, including the categories of organisations with which we may share data, is set out in the Home Office personal information charter https://www.gov.uk/government/organisations/home-office/about/personal-information-charter and, for the Borders, Immigration and Citizenship System (BICS), including the EU Settlement Scheme, via the BICS privacy information notice: https://www.gov.uk/government/publications/personal-information-use-in-borders-immigration-and-citizenship.
Identifying the precise number of instances in which data has been shared proactively with another government department would involve the interrogation of an array of disparate IT systems and would therefore be disproportionately costly.