Facebook and WhatsApp, recognised as popular social media and messaging platforms, are increasingly being used as online sales platforms through the emergence of marketplaces, online stores and groups. Businesses and individual sellers create groups on these platforms to attract buyers who share similar interests, but the buyers and sellers often do not know one another, which may cause trust issues. Therefore, sellers should be aware of the factors that influence a buyer’s trust so that strategies can be developed to mitigate trust issues that may hinder sales transactions. The aim of this study was to investigate the influence of information quality, perceived ease of use and usefulness on consumers’ trust in Facebook and WhatsApp groups as online sales platforms. Following a descriptive research design, the data was gathered from 412 participants by means of an electronic self-administered questionnaire that was distributed to the South African database of an international research company. The statistical methods that were used to analyse the data included reliability measures, HTMT analysis and structural equation modelling. The findings of the study revealed that the information quality and perceived ease of use of WhatsApp and Facebook groups significantly influence the perceived usefulness of these groups, which, in turn, influences consumers’ trust in WhatsApp and Facebook groups as online sales platforms. In conclusion, by understanding the relationship between these factors, social media platforms could alter their group features, while businesses and individual sellers can improve their marketing strategies to instil trust among group members and ultimately increase sales.