AP and PO matching tax calculation

User_PC1MG

We have integrated tax calculation with the third party tax engine for Purchase Orders and AP invoices. While the PO tax calculation is functioning correctly, we are encountering an error when matching invoices to Purchase Orders. Oracle is reporting a tax calculation issue with the message: "The Tax couldn't be calculated, calc_tax_variance_factors -1427-01427, single-row subquery returns more than one row.

The tax calculation couldn't be completed. (ZX-885378)." This occurs when a single PO item line has two tax lines for the same tax, which is a valid business scenario. For example, external tax engine returns two tax lines for import reverse charge situations where VAT is not charged by the supplier but must be reversed by the buyer, or for domestic purchases from unregistered suppliers in specific countries.

This issue affects multiple countries, and we are working with 40+ countries in this implementation.