Find below a list of enforcement bodies.
Pay and work right complaints can be made via the online form: https://www.gov.uk/government/publications/pay-and-work-rights-complaints.
Use the online form to complain about not being paid the National Minimum Wage, employment agencies, gangmasters or working hours. Complaints can be anonymous and made by third parties but are easier to investigate if they are made by the worker themselves. Also, workers can raise concerns via ACAS helpline: 0300 123 1100.
If workers are in situation of modern slavery and do not want to contact the Gangmasters and Labour Abuse Authority (GLAA) they can go to the police who also investigate modern slavery. There is also the modern slavery helpline: 08000 121 700.