Alternative populations

Alternative population bases are different geographical locations where individuals could have been counted for Census 2021, other than their usual residence. We plan to release data on five types of alternative populations.


The short-term resident population are those who were not born in the UK and who intend to stay in the UK for less than 12 months.


The workplace population is an estimate of the usually resident population aged 16 years and over, working in an area. It includes people who work mainly at or from home, or do not have a fixed place of work, in their area of usual residence.


The workday population is an estimate of the population during the working day. It includes everybody who works in an area, wherever they usually live, and all respondents who live in the area but do not work.


The out-of-term population is the usually resident population, redistributed to their out-of-term address if they have one. As a result, the difference relates to the location of some students and schoolchildren.

Second address

The second address population looks at the characteristics of the population with a second address, including the characteristics of the second address itself. When producing datasets on the characteristics of the population with a second address, we count them at the location of their second address rather than at the address where they are usually resident.

Small populations

Small populations are groups that are defined by their cultural background, including characteristics such as:

  • ethnic group

  • country of birth

  • religion

  • national identity

To protect the identity of individuals in these small population sizes, we do not release detailed information on these groups in the standard outputs.

Instead, we will create bespoke datasets for specific small populations, at all geographies where the number of that population exceeds a set threshold.

Datasets we will produce

We are committed to producing datasets on these population groups:

  • Cornish, defined using national identity

  • Jain, defined using ethnic group or religion

  • Kashmiri, defined using ethnic group

  • Nepali and Nepalese (includes Gurkha), defined using ethnic group

  • Ravidassia, defined using religion

  • Sikh, defined using ethnic group or religion

We aim to produce datasets on these groups down to Middle layer Super Output Area (MSOA) geography.

We are also committed to producing small population datasets at local authority level by five-year age bands by sex, for the same 30 population groups as we produced for 2011 Census. These 17 groups by country of birth and 13 groups by ethnicity are listed under the Small population datasets - part 1 section on the NOMIS website.

Where and when to find the data

Users will be able to find and download data on alternative population bases and small populations from the ONS website.

We plan to release most of the data from alternative population bases and small populations during phase three of the Census 2021 outputs release schedule. This will take place after we have released the multivariate data on the usual resident population.

Following user feedback, we plan to bring forward the release of data on the short-term population from phase three, into phase two.

More information

If you need more information about our plans for Census 2021 alternative population bases or small populations, please contact us at