Question to the HM Treasury:

To ask Mr Chancellor of the Exchequer, how many people had investments in cash ISAs in the 2016-17 financial year.

HMRC publish National Statistics on ISA account subscriptions and the number of ISAs held by individuals.

Table 9.10 from the ISA statistics shows, for the latest year available (2014-15) over 19 million individuals held Cash ISAs.

https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/610482/Table_9.10_2014-15_for_publication.pdf

The number of individuals holding Cash ISAs in 2016-17 is expected to be published in April 2019.