I would try to follow the steps below:
- Increase strategy roles in your CV – ideally with no profit activities or free advisory for startups. If you have already sufficient strategy/consulting elements in your CV you can skip this step.
- Practice on case and fit questions – at the following links you can find some tips on how to get started for case interviews:
- Network with current consultants in order to receive a referral
If you manage to receive an offer, you will likely join as an Analyst (McK) or Associate (BCG) with 1-1.5 years of experience in the firm. If the previous steps do not work, it could be useful to apply for an MBA and try again after that, targeting an Associate (McK) or Consultant (BCG) position.
As for Chartership, I don’t think it could have a relevant impact on the application.
Hope this helps,