How do I edit a company's identity and branding?

Go to Tenant Management and click the company, then Edit. From the identity control centre you can change the display name, legal name, code, type, country, currency, language and timezone, contact details, theme colours and logo, and the white-label toggle. Every change is recorded in the company's history — for example a rename is logged as 'Renamed X to Y'. This means you always have an audit trail of who changed what and when. Changing the code affects how references are generated going forward; existing references are not rewritten.