Use the ReducedTotals Extension to model this information.

Elements

Element	Description
Extended Legal; Monetary Totals Group (`Invoice/UBLExtensions/UBLExtension/ExtensionContent/InvoiceExtension/ ReducedTotals/LegalMonetaryTotal/`)	Groups extended legal monetary totals.
Tax Exclusive Amount (`Invoice/UBLExtensions/UBLExtension/ExtensionContent/InvoiceExtension/ ReducedTotals/LegalMonetaryTotal/TaxExclusiveAmount`)	Specify the difference between the total amounts of the current and of the preceding, corresponding advance payment invoice, in the final invoice.
Tax Exclusive Amount Currency (`Invoice/UBLExtensions/UBLExtension/ExtensionContent/InvoiceExtension/ ReducedTotals/LegalMonetaryTotal/TaxExclusiveAmount [@currencyID]`)	Specify the currency.
Tax Inclusive Amount (`Invoice/UBLExtensions/UBLExtension/ExtensionContent/InvoiceExtension/ ReducedTotals/LegalMonetaryTotal/TaxInclusiveAmount`)	Specify the difference between the total amounts of the current and of the preceding, corresponding advance payment invoice, in the final invoice.
Tax Inclusive Amount Currency (`Invoice/UBLExtensions/UBLExtension/ExtensionContent/InvoiceExtension/ ReducedTotals/LegalMonetaryTotal/TaxInclusiveAmount [@currencyID]`)	Specify the currency.
Payable Amount (`Invoice/UBLExtensions/UBLExtension/ExtensionContent/InvoiceExtension/ ReducedTotals/LegalMonetaryTotal/PayableAmount`)	Specify the difference between the total amounts of the current and of the preceding, corresponding advance payment invoice, in the final invoice.
Payable Amount Currency (`Invoice/UBLExtensions/UBLExtension/ExtensionContent/InvoiceExtension/ ReducedTotals/LegalMonetaryTotal/PayableAmount [@currencyID]`)	Specify the currency.
Payable Amount Including Third Party Payments (`Invoice/UBLExtensions/UBLExtension/ExtensionContent/InvoiceExtension/ ReducedTotals/LegalMonetaryTotal/PayableAmountIncludingThirdPartyPayment`)	Specify the payable for third-party payments in Germany.
Payable Amount Including Third Party Payments Currency (`Invoice/UBLExtensions/UBLExtension/ExtensionContent/InvoiceExtension/ ReducedTotals/LegalMonetaryTotal/PayableAmountIncludingThirdPartyPayment [@currencyID]`)	Specify the currency.

Example

<ubl:Invoice>
    <cec:UBLExtensions>
        <cec:UBLExtension>
            <cec:ExtensionContent>
                <vrbl:InvoiceExtension>
                    <!-- Code omitted for clarity -->
                    <vrbl:ReducedTotals>
                        <cac:LegalMonetaryTotal>
                            <cbc:TaxExclusiveAmount currencyID="RSD">10490</cbc:TaxExclusiveAmount>
                            <cbc:TaxInclusiveAmount currencyID="RSD">10280</cbc:TaxInclusiveAmount>
                            <cbc:PayableAmount currencyID="RSD">10280</cbc:PayableAmount>
                        </cac:LegalMonetaryTotal>
                    <vrbl:ReducedTotals>    
                    <!-- Code omitted for clarity -->    
                </vrbl:InvoiceExtension>
            </cec:ExtensionContent>
        </cec:UBLExtension>    
    </cec:UBLExtensions>
    <!-- Code omitted for clarity -->
</ubl:Invoice>