It is usually office-specific rather than an MBB-wide rule. The practical question is whether consultants in that office need to work with clients, regulators, suppliers, or local teams in a language other than English. If the answer is yes, language ability can become a real staffing requirement rather than a nice-to-have.

Before applying, check the job posting and ask recruiting directly. The broader issues for cross-border candidates are covered in this guide to international consulting recruiting and visa considerations.

If you speak the language but are worried about professional fluency, focus on whether you can communicate clearly in interviews and client settings. CaseBasix also has a guide on improving clarity when English is not your first language.

Do not assume that an international office is automatically easier to enter. A credible reason for the location, work authorization, and language fit all need to line up.

Very office dependent. Singapore and Dubai can be different from offices where almost all client work is in the local language.

I would email recruiting before spending weeks networking. They usually answer language eligibility pretty clearly.