Modern slavery is a complex crime that covers all forms of slavery, trafficking and exploitation. Currently, there is no definitive source of data or suitable method available to accurately quantify the number of victims of offences that fall under modern slavery in the UK. The hidden nature of the crime makes producing an accurate prevalence measure difficult. Instead, the Office for National Statistics (ONS) has brought together a range of available data sources on known victims and cases of modern slavery to provide a better understanding of the extent and nature of the crime. See the Modern slavery in the UK - March 2020 article and appendix tables for the data.
Key findings from the article include -
  • Greater awareness, increases in reporting and improvements in police recording are likely to have contributed to the increases seen in potential victim numbers in the UK since the introduction of the modern slavery Acts across the UK in 2015.
  • The number of potential victims referred through the UK National Referral Mechanism (NRM) increased by 36% to 6,985 in the year ending December 2018. Almost half of the referrals (45%) were potential victims aged under 18 years (see Appendix table 1). (Source - Home Office – UK)
  • In the year ending June 2019, 55% of potential adult victims supported in England and Wales were female and 44% were male (see Appendix table 36). The type of exploitation experienced varied by sex of victim. For example, in the year ending June 2019, domestic servitude and sexual exploitation were predominantly experienced by females (83% and 98% respectively), whereas labour exploitation was mostly experienced by males (86%) (see Figure 7 of the article and Appendix table 39). (Source - The Salvation Army - England and Wales).
Professor Sir Bernard Silverman, a leading academic in the field of modern slavery, has also published a supporting blog on Understanding the nature of modern slavery in the UK.

This table provides metadata for the actual indicator available from UK statistics closest to the corresponding global SDG indicator. Please note that even when the global SDG indicator is fully available from UK statistics, this table should be consulted for information on national methodology and other UK-specific metadata information.

Indicator available
Indicator description
Geographical coverage
Unit of measurement
Available disaggregations
Other information

Data follows the UN specification for this indicator. This indicator has been identified in collaboration with topic experts.

Data last updated 18 April 2019
Metadata last updated 09 December 2020

This table provides information on metadata for SDG indicators as defined by the UN Statistical Commission. Complete global metadata is provided by the UN Statistics Division.

Indicator name

Number of victims of human trafficking per 100,000 population, by sex, age and form of exploitation

Target name

End abuse, exploitation, trafficking and all forms of violence against and torture of children

Global indicator description
UN designated tier

Tier II

UN custodian agency

United Nations Office on Drugs and Crime (United Nations Office for Disarmament Affairs (UNODC))

Link to UN metadata United Nations Sustainable Development Goals metadata for target 16.2 opens in a new window