How can i buy food in bulk in the uk?

Individuals can join Macro or Costco if they work in certain professions like the NHS, Police, fire service or civil service. Apparently you need to take in 3 payslips. Perhaps you or another householder does. See their website for more info. Also if it is just for you, remember that a lot of food loses quality over time, even stuff like Rice and pasta, so you may not really benefit from buying in large quanties. I buy stuff at Booker (for a catering business) but don't really find it cheaper than say Aldi, it just comes in handy larger quantities.