In plain English
It is the number used to tell one invoice apart from another. Each one refers to a single invoice, not to invoices in general.
In context
Here, it names the identifying number assigned to that specific invoice.
- Situation
- Understanding invoices, billing statements, balances, due dates, credits, and receipts
- What it communicates
- labels the unique identifier for a specific invoice
Meaning limits
By itself, the term does not say who assigned the number or what format it has.
Examples
“Invoice number 1048 belongs to the March repair bill, not the February one.”
“Her email about the unpaid bill included the invoice number.”