diff --git a/.github/workflows/ruby.yml b/.github/workflows/ruby.yml
index a12b36c..fa6a47f 100644
--- a/.github/workflows/ruby.yml
+++ b/.github/workflows/ruby.yml
@@ -58,6 +58,7 @@ jobs:
         gem install nokogiri -v '~> 1.11.3'
         gem install savon
         gem install webmock
+        gem install mocha
         gem install minitest -v '~> 5.14'
         bundle install
         rake
diff --git a/CHANGELOG.md b/CHANGELOG.md
index dc304a4..38d6477 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,6 @@
+03.10.2023
+* Added Balance element to InvoiceSumGroup [#41] (https://github.com/internetee/e_invoice/pull/41)
+
 26.09.2023
 * Updated wsdl test address [#36](https://github.com/internetee/e_invoice/pull/36)
 
diff --git a/estonian_e_invoice.gemspec b/estonian_e_invoice.gemspec
index 99016c6..d1e098e 100644
--- a/estonian_e_invoice.gemspec
+++ b/estonian_e_invoice.gemspec
@@ -32,7 +32,8 @@ Gem::Specification.new do |spec|
   spec.add_runtime_dependency 'savon'
   spec.add_development_dependency 'bundler', '>= 2.2.10'
   spec.add_development_dependency 'minitest', '~> 5.0'
+  spec.add_development_dependency 'mocha'
   spec.add_development_dependency 'rake', '~> 13.0'
   spec.add_development_dependency 'simplecov'
   spec.add_development_dependency 'webmock'
-end
\ No newline at end of file
+end
diff --git a/lib/e_invoice/generator.rb b/lib/e_invoice/generator.rb
index b2522ec..bb70931 100644
--- a/lib/e_invoice/generator.rb
+++ b/lib/e_invoice/generator.rb
@@ -108,14 +108,36 @@ def build_invoice_details(invoice)
 
     def build_invoice_totals(invoice)
       builder.InvoiceSumGroup do
+        build_invoice_balance(invoice)
         builder.InvoiceSum format_decimal(invoice.subtotal, scale: 4)
         builder.TotalVATSum format_decimal(invoice.vat_amount)
         builder.TotalSum format_decimal(invoice.total)
-        builder.TotalToPay format_decimal(invoice.payable == false ? 0 : invoice.total)
+        if invoice.payable == false
+          builder.TotalToPay format_decimal(0)
+        else
+          builder.TotalToPay format_decimal(invoice.total_to_pay || invoice.total)
+        end
         builder.Currency invoice.currency
       end
     end
 
+    def build_invoice_balance(invoice)
+      builder.Balance do
+        build_element('BalanceDate', invoice.balance_date)
+        build_element('BalanceBegin', invoice.balance_begin, :format_decimal)
+        build_element('Inbound', invoice.inbound, :format_decimal)
+        build_element('Outbound', invoice.outbound, :format_decimal)
+        build_element('BalanceEnd', invoice.balance_end, :format_decimal)
+      end
+    end
+
+    def build_element(name, value, format_method = nil)
+      return unless value
+
+      formatted_value = format_method ? send(format_method, value) : value
+      builder.__send__(name, formatted_value)
+    end
+
     def build_invoice_payment_details(invoice)
       builder.PaymentInfo do
         builder.Currency invoice.currency
@@ -123,7 +145,11 @@ def build_invoice_payment_details(invoice)
         builder.PaymentDescription invoice.number
         builder.Payable invoice.payable == false ? 'NO' : 'YES'
         builder.PayDueDate invoice.due_date
-        builder.PaymentTotalSum format_decimal(invoice.payable == false ? 0 : invoice.total)
+        if invoice.payable == false
+          builder.PaymentTotalSum format_decimal(0)
+        else
+          builder.PaymentTotalSum format_decimal(invoice.total_to_pay || invoice.total)
+        end
         builder.PayerName invoice.payer_name
         builder.PaymentId invoice.number
         builder.PayToAccount invoice.beneficiary_account_number
@@ -203,7 +229,7 @@ def build_footer(e_invoice)
     end
 
     def format_decimal(decimal, scale: 2)
-      format("%.#{scale}f", decimal)
+      format("%.#{scale}f", decimal) if decimal
     end
   end
-end
\ No newline at end of file
+end
diff --git a/lib/e_invoice/invoice.rb b/lib/e_invoice/invoice.rb
index fd79557..9590f3f 100644
--- a/lib/e_invoice/invoice.rb
+++ b/lib/e_invoice/invoice.rb
@@ -4,8 +4,9 @@ class Invoice
                   :date, :recipient_id_code, :reference_number,
                   :due_date, :payable, :payer_name,
                   :beneficiary_name, :beneficiary_account_number,
-                  :subtotal, :vat_amount, :total, :currency,
-                  :monthly_invoice
+                  :subtotal, :vat_amount, :total, :total_to_pay, :currency,
+                  :balance_date, :balance_begin, :inbound, :outbound,
+                  :balance_end, :monthly_invoice
 
     alias_method :id, :number
 
@@ -35,4 +36,4 @@ def validate_delivery_channels(channels)
       end
     end
   end
-end
\ No newline at end of file
+end
diff --git a/lib/e_invoice/version.rb b/lib/e_invoice/version.rb
index 10a5716..ce30362 100644
--- a/lib/e_invoice/version.rb
+++ b/lib/e_invoice/version.rb
@@ -1,3 +1,3 @@
 module EInvoice
-  VERSION = '0.1.4'.freeze
+  VERSION = '0.1.5'.freeze
 end
diff --git a/test/generator_test.rb b/test/generator_test.rb
index 16f5032..c996388 100644
--- a/test/generator_test.rb
+++ b/test/generator_test.rb
@@ -75,7 +75,13 @@ def invoice(payable: @payable)
       invoice.subtotal = 100
       invoice.vat_amount = 20
       invoice.total = 120
+      invoice.total_to_pay = nil
       invoice.delivery_channel = :internet_bank
+      invoice.balance_date = nil
+      invoice.balance_begin = nil
+      invoice.inbound = nil
+      invoice.outbound = nil
+      invoice.balance_end = nil
     end
   end
 
@@ -160,6 +166,7 @@ def test_generates_e_invoice_xml
             </Extension>
           </InvoiceInformation>
           <InvoiceSumGroup>
+            <Balance/>
             <InvoiceSum>100.0000</InvoiceSum>
             <TotalVATSum>20.00</TotalSum>
             <TotalSum>120.00</TotalSum>
@@ -274,6 +281,7 @@ def test_generates_prepaid_e_invoice_xml
             </Extension>
           </InvoiceInformation>
           <InvoiceSumGroup>
+            <Balance/>
             <InvoiceSum>100.0000</InvoiceSum>
             <TotalVATSum>20.00</TotalSum>
             <TotalSum>120.00</TotalSum>
@@ -329,6 +337,128 @@ def test_generates_prepaid_e_invoice_xml
     assert_equal expected_xml, actual_xml
   end
 
+  def test_generates_prepaid_e_invoice_xml_with_balance_inbound
+    expected_xml = <<~XML
+      <?xml version="1.0" encoding="UTF-8"?>
+      <E_Invoice xsi:noNamespaceSchemaLocation="e-invoice_ver1.2.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+        <Header>
+          <Date>2010-07-05</Date>
+          <FileId>id1234</FileId>
+          <Version>1.2</Version>
+        </Header>
+        <Invoice invoiceId="invoice-1234" regNumber="recipient-1234" sellerRegnumber="john-1234" serviceId="1234">
+          <InvoiceParties>
+            <SellerParty>
+              <Name>John Doe</Name>
+              <RegNumber>john-1234</RegNumber>
+              <VATRegNumber>US1234</VATRegNumber>
+                <ContactData>
+                  <LegalAddress>
+                    <PostalAddress1>seller address line1</PostalAddress1>
+                    <PostalAddress2>seller address line2</PostalAddress2>
+                    <City>seller address city</City>
+                    <PostalCode>12345</PostalCode>
+                    <Country>seller address country</Country>
+                  </LegalAddress>
+                </ContactData>
+            </SellerParty>
+            <BuyerParty>
+              <Name>Jane Doe</Name>
+              <RegNumber>1234</RegNumber>
+              <VATRegNumber>US1234</VATRegNumber>
+                <ContactData>
+                  <E-mailAddress>info@buyer.test</E-mailAddress>
+                  <LegalAddress>
+                    <PostalAddress1>buyer address line1</PostalAddress1>
+                    <PostalAddress2>buyer address line2</PostalAddress2>
+                    <City>buyer address city</City>
+                    <PostalCode>123456</PostalCode>
+                    <Country>buyer address country</Country>
+                  </LegalAddress>
+                </ContactData>
+                <AccountInfo>
+                  <AccountNumber>GB33BUKB20201555555555</AccountNumber>
+                </AccountInfo>
+            </BuyerParty>
+          </InvoiceParties>
+          <InvoiceInformation>
+            <Type type="DEB"/>
+            <DocumentName>ARVE</DocumentName>
+            <InvoiceNumber>invoice-1234</InvoiceNumber>
+            <PaymentReferenceNumber>1234</PaymentReferenceNumber>
+            <InvoiceDate>2010-07-06</InvoiceDate>
+            <DueDate>2010-07-07</DueDate>
+            <Extension extensionId="eakChannel">
+              <InformationContent>INTERNET_BANK</InformationContent>
+            </Extension>
+            <Extension extensionId=\"eakStatusAfterImport\">
+              <InformationContent>SENT</InformationContent>
+            </Extension>
+          </InvoiceInformation>
+          <InvoiceSumGroup>
+            <Balance>
+              <Inbound>60.00</Inbound>
+            </Balance>
+            <InvoiceSum>100.0000</InvoiceSum>
+            <TotalVATSum>20.00</TotalSum>
+            <TotalSum>120.00</TotalSum>
+            <TotalToPay>60.00</TotalToPay>
+            <Currency>EUR</Currency>
+          </InvoiceSumGroup>
+          <InvoiceItem>
+            <InvoiceItemGroup>
+              <ItemEntry>
+                <Description>acme services</Description>
+                <ItemDetailInfo>
+                  <ItemUnit>pc</ItemUnit>
+                  <ItemAmount>1.0000</ItemAmount>
+                  <ItemPrice>100.0000</ItemPrice>
+                </ItemDetailInfo>
+                <ItemSum>100.0000</ItemSum>
+                <VAT vatId="TAX">
+                  <VATRate>20.00</VATRate>
+                  <VATSum>20.0000</VATSum>
+                </VAT>
+                <ItemTotal>120.0000</ItemTotal>
+              </ItemEntry>
+            </InvoiceItemGroup>
+            <InvoiceItemTotalGroup>
+              <InvoiceItemTotalAmount>120.0000</InvoiceItemTotalAmount>
+              <InvoiceItemTotalSum>100.0000</InvoiceItemTotalSum>
+              <InvoiceItemTotal>120.0000</InvoiceItemTotal>
+            </InvoiceItemTotalGroup>
+          </InvoiceItem>
+          <PaymentInfo>
+            <Currency>EUR</Currency>
+            <PaymentRefId>1234</PaymentRefId>
+            <PaymentDescription>invoice-1234</PaymentDescription>
+            <Payable>YES</Payable>
+            <PayDueDate>2010-07-07</PayDueDate>
+            <PaymentTotalSum>60.00</PaymentTotalSum>
+            <PayerName>John Smith</PayerName>
+            <PaymentId>invoice-1234</PaymentId>
+            <PayToAccount>GB33BUKB20201555555556</PayToAccount>
+            <PayToName>Acme Ltd</PayToName>
+          </PaymentInfo>
+        </Invoice>
+        <Footer>
+          <TotalNumberInvoices>1</TotalNumberInvoices>
+          <TotalAmount>120.00</TotalAmount>
+        </Footer>
+      </E_Invoice>
+    XML
+
+    e_invoice = EInvoiceDouble.new(payable: true)
+    EInvoice::Invoice.any_instance.stubs(:total_to_pay).returns(60)
+    EInvoice::Invoice.any_instance.stubs(:inbound).returns(60)
+
+    actual_xml = Nokogiri::XML(@generator.generate(e_invoice)) { |config| config.noblanks }
+                   .to_xml
+
+    expected_xml = Nokogiri::XML(expected_xml) { |config| config.noblanks }.to_xml
+    assert_equal expected_xml, actual_xml
+  end
+
   def test_generated_xml_conforms_to_estonian_e_invoice_standard_v1_2
     schema = Nokogiri::XML::Schema(File.read('test/xml_schemas/v1.2.xsd'))
     xml = @generator.generate(EInvoiceDouble.new)
@@ -337,4 +467,4 @@ def test_generated_xml_conforms_to_estonian_e_invoice_standard_v1_2
     valid = errors.empty?
     assert valid, proc { errors.each { |error| puts error } }
   end
-end
\ No newline at end of file
+end
diff --git a/test/test_helper.rb b/test/test_helper.rb
index 9a1cf15..e6c27d4 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -6,4 +6,5 @@
 $LOAD_PATH.unshift File.expand_path('../../lib', __FILE__)
 require 'e_invoice'
 require 'minitest/autorun'
-require 'webmock/minitest'
\ No newline at end of file
+require 'webmock/minitest'
+require 'mocha/minitest'
\ No newline at end of file