What documents do I need to open a business bank account?

Requirements vary by entity, but banks generally ask for your EIN (or SSN for a sole proprietor without an EIN), a government-issued photo ID, and proof the business exists. For an LLC or corporation that means formation documents like articles of organization or incorporation, and often an operating agreement or corporate resolution authorizing account opening. Sole proprietors using a trade name may need a 'doing business as' (DBA) certificate. Bring your business address and, for partnerships or multi-member LLCs, IDs for other owners. Some banks require an initial deposit. Having your EIN letter from the IRS ready speeds things up. Call ahead, since documentation lists differ and coming prepared avoids a wasted trip.