If you have good grades and they were passed within 2 years you will be exempt from the ICB Level 1 and be able to join as an Affiliate.
You could then continue with the ICB route taking the ICB's Level 2 papers, or carry on with IAB and get further exemptions as you complete more IAB papers.
You would need ICB Level 2 and then join the ICB at Associate Level to get a practice license and become self employed. At Affiliate level you would be more of a data inputter or junior bookkeeper.
Contact the ICB on 0845 060 2345 if you have any questions.