If an inventory item does not arrive on site or the wrong quantity comes, log it as a shortage. Shortages are tracked separately from inventory check-ins. They live in the Issues tab of the event, not the Inventory tab.
For step-by-step instructions on logging a shortage from the dashboard or the mobile app, see Logging a shortage on an event.
Shortage vs inventory check-in
These are two separate things in Vantage:
Inventory check-in — confirms what arrived. Done from the Inventory tab.
Shortage — flags what did not arrive or came in the wrong quantity. Done from the Issues tab.
Your field team can log a shortage regardless of whether the missing item was in the inventory list; shortages are not limited to items that were pre-added.