Many funders have requirements, or preferences, around whether outputs arising from research they fund need to be made open access or not. In general, information on this will be included in the grant award, but may be hard to find or confusing.
An easier way to get an overview of your funder’s open access requirements is to consult the SHERPA/JULIET database: http://www.sherpa.ac.uk/juliet/
Their website provides access to an easy-to-understand list of all major research funders' policies on open access availability of work they fund. It covers both UK and international funders, including charities, UK Research and Innovation, and some industry-based funders.
Researchers funded by Arthritis Research UK, Breast Cancer Campaign, British Heart Foundation, Cancer Research UK or Leukaemia & Lymphoma Research may have heard of the Charity Open Access Fund (COAF). These charities, along with the Wellcome Trust, have established a fund to provide block grants to cover open access costs for the main institutions that they fund; this is in a two-year pilot. Currently, UEA does not receive a block grant from COAF and so researchers in receipt of funding from one of these charities should seek advice from the open research team in RIN about the best way to cover their open access costs.