For unverified corporate groups, no more than 5 users can be assigned to a card. You can get verified by Grab for Work and allow up to 50 users to a single card.
This is to prevent your corporate card from being blocked by the bank as a result of multiple transactions within a short period of time from multiple locations. Banks may detect this as fraudulent activity and deny transactions.
To verify your group, write to us at firstname.lastname@example.org with your registered company name (in full) with the email subject as Request to Verify Group and your application to increase the number of users use of your card.