Changing major

Based on the most helpful WSO content, banks typically do not rescind offers due to changes in your major, especially if you are maintaining a strong academic record and relevant coursework. What matters most is your ability to demonstrate the skills and knowledge required for the role, as well as your commitment to the industry.

However, if you have already accepted an offer, it’s a good idea to inform the bank about the change proactively. Transparency is key, and as long as the change doesn’t significantly alter your qualifications or the perception of your candidacy, it’s unlikely to be an issue.

Sources: Reconsidering banking after receiving offer... help?, Bank withdrawing signed/accepted offer?, Accounting major, can't seem to break into IB, Current IBankers: What would you do if a summer candidate reneged another offer to sign with your firm?, UChicago or Brown for undergrad?