Social network-based HIV testing is an approach for engaging sexual and drug injecting partners and social contacts of key population members with HIV and of those who are HIV-negative and at ongoing risk in voluntary HTS. By addressing people’s confidentiality concerns and broadening the reach to social contacts, social network-based HIV testing approaches can improve the acceptability of partner services among key populations and so reach more people who may not otherwise test for HIV. WHO now recommends that social network-based HIV testing approaches can be offered for key populations