Explanation (150–250 words)
In Salesforce Billing, tax computation can be handled internally using the Salesforce Tax Engine or externally via integration through the Billing TaxEngineAdapter Apex interface.
When a company uses a custom tax application and wants Salesforce Billing to respect its calculated taxes, the correct and scalable approach is to integrate the custom app directly with this interface.
The TaxEngineAdapter allows Salesforce Billing to call an external system during invoice generation to retrieve tax amounts and details, which are then automatically included in the Invoice Line Tax records. This ensures taxes are calculated, stored, and posted correctly for both existing and new products without manual CSV imports.
Exact Extract from Salesforce Billing Implementation Guide:
“Use the TaxEngineAdapter Apex interface to integrate external tax calculation engines with Salesforce Billing. The adapter is invoked automatically during invoice generation to compute and apply taxes.”
es:
Salesforce Billing Implementation Guide — Tax Engine Integration and TaxEngineAdapter Interface
Salesforce Revenue Cloud Developer Guide — External Tax Service Integration
Salesforce Billing Data Model — Invoice and Tax Line Relationships
