First Invoice counter Value

When starting the integration, what should be the initial value assigned to the invoice counter value?

Invoice counter value is expected to be numerical value and cannot be reset (example 1,2,3,4,5,6…). The initial value = 1. However, there is no upfront validation on the order in which invoices are submitted. It can be submitted in any order. And each device issuing invoices should have its own counter value.

Thank you, Sarah, for your reply. Are you a ZATCA consultant or a regular user?