More than 5 million adults lack both functional literacy (below level 1) and numeracy (below entry level 3); an estimated 11.5 million adults do not have basic digital skills; and one in five adults do not have basic financial capabilities. Around 850,000 people have English for Speakers of Other Languages (ESOL) needs. At the same time, participation in adult Maths and English is falling. This review draws on the best available evidence on basic skills approaches to look at what types of approach are most effective and, where possible, most cost-effective. The review also uses a wider range of evaluations to set out the issues that should be taken into consideration when delivering basic skills programmes. Much of the literature has advocated the general benefits of adult learning rather than analysed what works in terms of different approaches. For the delivery of adult basic skills training to be successful, programmes need to motivate adults to take part, convey the benefits of basic skills effectively, and encourage adults to persist in the programme.