What are the accepted GCSE's equivalent options? I can’t find this in the entry requirements or FAQ’s. Thanks

For example, are level 3/4 certificates and diplomas, or level 2 Functional Skills accepted? The UK gov website suggests these are equivalent or higher grades but I am unsure of these are accepted by BA.

You would have to check using the following website for any international GCSE equivalents https://www.enic-naric.net however I believe that the only UK accepted certificates would be GCSEs.