Checkout this documentation.
A brief use case:
A company, who has more than 2500 clients, sells products only to customers through a private website. Invitations are sent to them to register to the website. In Odoo they need to be granted portal access to make that registration.
In the following documentation, you'll find how to import a list of portal users and how to masively grant them portal access.
Documentation:https://docs.google.com/document/d/1Gck7C-iYdXyIW_1U4IhDYGeBZ7dI0aG3OYsUdkS-ANg/edit
nice. but with 40000 customers, it becomes more difficult. It's not possible to create a server action directly from “Contacts”?
Thanks
Ricardo
It should work with that amount of records as well, you might have to index your import file but it should be fine. If you use the server action from contacts you would still have to go one by one to grant portal access so it´s not doable really.