How To Fix WP109 - Billing doc. contains no items

WP109 - Overview

• Message type: E = Error

• Message class: WP - Messages from POS interface

• Message number: 109

• Message text: Billing doc. contains no items

What causes this issue?

The invoice contains no items.

System Response

The system did not post the invoice.

How to fix this error?

Using error/status reporting, check whether errors occurred while the
billing document items were being prepared. Correct the errors and
<DS:TRAN.WPIA>repeat inbound processing </>.
If no errors have been logged, the IDoc may not contain any items. You
can check this by <DS:TRAN.WE21>viewing the relevant IDoc areas</>.

Error message extract from SAP system. Copyright SAP SE.

WP109 - Details

• The SAP error message WP109, which states "Billing document contains no items," typically occurs when you attempt to create or process a billing document (such as an invoice) that does not have any line items associated with it. This can happen in various scenarios, such as during the billing process for sales orders, delivery documents, or service orders.
  Causes:
  
  No Sales Order Items: The sales order or delivery document that you are trying to bill does not have any items or has been completely billed already.
  Incorrect Document Type: The document type used for billing may not be appropriate for the items you are trying to bill.
  Data Entry Errors: There may have been an error in data entry, leading to the creation of a billing document without any items.
  Incomplete Document: The document may not have been fully processed or may be in a status that does not allow for billing.
  
  Configuration Issues: There may