The law provides for a census to be taken not less than five years after the previous census. However, every census requires further legislation which details how a particular census is to be run. A census is taken in Scotland by the Registrar General for Scotland under the Census Act 1920.
The Census (Amendment) (Scotland) Bill
As announced by the First Minister as part of the 2018-19 Programme for Government, the Census (Amendment) (Scotland) Bill (link to the Scottish Parliament website) would amend the Census Act 1920 to allow National Records of Scotland (NRS) to ask voluntary questions on sexual orientation and transgender status/history in the 2021 census and future censuses. The Bill has now been introduced to the Scottish Parliament.
The full set of questions currently proposed to be asked in the 2021 Census can be found on the Plans for Scotland's Census 2021 page. The final proposed questions will be laid before the Scottish Parliament for agreement before the census takes place.
To support the introduction of the Census (Amendment) (Scotland) Bill, NRS has published a range of Impact Assessments, which can be viewed below: