In standard Dynamics 365 Finance:

• During invoice entry (before posting):
• Users can only view and adjust tax amounts in document currency
• There is no option to enter or override the tax amount directly in the tax currency
• After posting:
• Tax amounts are displayed in document, accounting, and tax currency
• The tax currency amount is always system‑derived using exchange rates configured in D365 (based on invoice/posting date)

Even when the feature “Enable exchange rate types for sales tax” is enabled:

• The Adjust VAT option only applies to document currency
• Entering a tax amount in tax currency is treated as document currency
• The feature does not support capturing a tax amount that was externally calculated and legally binding

Requested enhancement

Provide a standard capability in Dynamics 365 Finance to:

• Allow manual entry or override of sales tax amounts directly in the tax currency during invoice entry
• Ensure the entered tax currency amount is:
• Preserved exactly as provided
• Used for statutory tax reporting
• Transparently derive corresponding document and accounting currency values based on the entered tax currency amount
• Clearly indicate when a tax currency value has been manually entered or overridden for audit and compliance purposes