https://www.odooclass.com/shop/product/configuring-odoo-for-multi-company-170

Hi,

For this what you have to do is that untick the common contact book from Settings -> General Settings.

By default this boolean field will be ticked, so all contacts will be visible in all companies. As you need separate contacts in each company, you can untick this boolean field.

See this: Set Company Dependent Products and Contacts in Odoo

Thanks