Hi,I want to make a career move from Internal Audit at a Big 4 firm to Consultancy (focusing on either Strategy, People, or Organisational Change).I have an ACA Qualification. However, I'm wondering if a qualification in project management or a certificate or PQ in management consultancy (http://www.iconsulting.org.uk/training_and_qualifications/about_ic_qualifications), or even an MBA would help open some doors for me to potential firms and help me get through the initial application stage? Alternatively, perhaps an additional qualification is a waste of time and I should focus on making myself marketable in other ways and more networking?

Your ACA will be enough to get you into a assistant manager/senior consultant equivalent role on the consulting track of big 4 rival firms - just apply

Yes, it is important to have good professional qualification from the best universities. Then you can get better opportunity for your career.