As you know, studying ACCA allows you to also get BHonors in Business degree in Oxford University if you pass the Skills level, and a Master in London University if you finish the Professional level. But in order to enroll on these two options a certificate on English language is required.
What certificate is needed for those who are living and studying in the UK but they are not born in the UK?
If you obtain the Oxford brooks university degree then you deemed to have an undergraduate degree from the UK which then exempts you from the English language certificate IELTS to pursue MSc degree.
I am not entirely sure about what is the requirements to opt for the Oxford books, but your best bet is to either look it up on the ACCA website or contact the ACCA helpline directly.