At least these four:
SVG: vector file, infinitely scalable, for print and signage.
PNG: transparent background, for digital use.
PDF: for print.
JPG: for social media and email.
Always ask for variants too: full colour, black and white, white on a dark background, and a square version for profile pictures. And for signage: a version in the specific spot colours (Pantone or PMS) if you're producing merchandise or large-format prints.
Store all files in a shared location everyone can access. The moment your team gets branding questions, you'll avoid the email round-trips.