I'm trying to send an invoice to my buyer and see them failing with the below error:

Status code="500" text="Internal Server Error">Error:null Please contact support with the Error Reference Number: ANERR-XXXXXXXXXXXXXXXX for more details</Status>

[ANCXML_HANDLER_ERROR] null -- ariba.network.common.cxml.CXMLDocException at ariba.network.service.common.antxnbusinesslogic.ANInvoiceRule.accumulatedPoItemInvoicedAmount(ANInvoiceRule.java:2149)

SAP Business Network

The cause of the issue can be:

• The invoice is sent for more than the remaining amount in the Purchase Order (PO).
• Mismatch of the invoice amount on Buyer and Supplier side. This can be caused if there are other invalid or failed invoices in the same Purchase Order, so it is important that documents that failed are properly rejected.
• <MaxAmount> for Blanket POs has lower limit than what supplier is sending in the invoice for the line item. This can happen specially on Amount Based Receiving scenarios where suppliers can enter amount directly.

Possible solutions:

• You must send the invoice with lower amount than the remaining amount of the Purchase Order for the line item.
• If the invoice amount is less than the remaining amount and you are still facing the issue, check the invoice status and their amount on the buyer and your account.
• Confirm that the amount being sent for the line item is not surpassing what is set as the Max Amount by the buyer on the Purchase Order (Blanket Purchase Orders). This can be checked by downloading the cXML payload of the Purchase Order and looking for the <MaxAmount> tag within the specific line item affected.
• Check if the below rules are enabled by your buyer for you as the invoice might require the Ship Notice or Receipt for the amount you are attempting to invoice:
  
  • Require suppliers to include only shipped quantities on invoices.
    
  • Require suppliers to include only received quantities on invoices.

SAP Business Network for Procurement & Supply Chain > Payments
SAP Business Network for Procurement & Supply Chain > Supply Chain Collaboration Starter Pack > SCC Starter Pack – Invoice and Payment
SAP Business Network for Procurement & Supply Chain > Transaction Documents
SAP Business Network for Procurement & Supply Chain > Transaction Documents > Transaction (Invoicing)