diff --git a/CRM/Civicase/Hook/BuildForm/AttachQuotationToInvoiceMail.php b/CRM/Civicase/Hook/BuildForm/AttachQuotationToInvoiceMail.php
new file mode 100644
index 000000000..9c36c431b
--- /dev/null
+++ b/CRM/Civicase/Hook/BuildForm/AttachQuotationToInvoiceMail.php
@@ -0,0 +1,63 @@
+<?php
+
+use Civi\Api4\CaseSalesOrder;
+use Civi\Api4\Contribution;
+
+/**
+ * Gives user the option to attach quotation to invoice mail.
+ */
+class CRM_Civicase_Hook_BuildForm_AttachQuotationToInvoiceMail {
+
+  /**
+   * Adds the Attach Quote checkbox to invoice mail form.
+   *
+   * @param CRM_Core_Form $form
+   *   Form Class object.
+   * @param string $formName
+   *   Form Name.
+   */
+  public function run(CRM_Core_Form &$form, $formName) {
+    if (!$this->shouldRun($formName)) {
+      return;
+    }
+
+    $form->add('checkbox', 'attach_quote', ts('Attach Quotation'));
+
+    CRM_Core_Region::instance('page-body')->add([
+      'template' => "CRM/Civicase/Form/Contribute/AttachQuotation.tpl",
+    ]);
+  }
+
+  /**
+   * Determines if the hook will run.
+   *
+   * @param string $formName
+   *   Form Name.
+   *
+   * @return bool
+   *   TRUE if the hook should run, FALSE otherwise.
+   */
+  private function shouldRun($formName) {
+    if ($formName != 'CRM_Contribute_Form_Task_Invoice') {
+      return FALSE;
+    }
+
+    $contributionId = CRM_Utils_Request::retrieve('id', 'Positive');
+    if (!$contributionId) {
+      return FALSE;
+    }
+
+    $salesOrder = Contribution::get()
+      ->addSelect('Opportunity_Details.Quotation')
+      ->addWhere('Opportunity_Details.Quotation', 'IS NOT EMPTY')
+      ->addWhere('id', '=', $contributionId)
+      ->addChain('salesOrder', CaseSalesOrder::get()
+        ->addWhere('id', '=', '$Opportunity_Details.Quotation')
+      )
+      ->execute()
+      ->first()['salesOrder'];
+
+    return !empty($salesOrder);
+  }
+
+}
diff --git a/CRM/Civicase/Hook/alterMailParams/AttachQuotation.php b/CRM/Civicase/Hook/alterMailParams/AttachQuotation.php
new file mode 100644
index 000000000..dcf2d8ecf
--- /dev/null
+++ b/CRM/Civicase/Hook/alterMailParams/AttachQuotation.php
@@ -0,0 +1,79 @@
+<?php
+
+use Civi\Api4\CaseSalesOrder;
+use Civi\Api4\Contribution;
+
+/**
+ * Adds Quotation invoice as an attachement.
+ */
+class CRM_Civicase_Hook_alterMailParams_AttachQuotation {
+
+  /**
+   * Attaches quotation to single invoice.
+   *
+   * @param array $params
+   *   Mail parameters.
+   * @param string $context
+   *   Mail context.
+   */
+  public function run(array &$params, $context) {
+    $shouldAttachQuote = CRM_Utils_Request::retrieve('attach_quote', 'String');
+
+    if (!$this->shouldRun($params, $context, $shouldAttachQuote)) {
+      return;
+    }
+
+    $rendered = $this->getContributionQuotationInvoice($params['tokenContext']['contributionId']);
+
+    $params['attachments'][] = CRM_Utils_Mail::appendPDF('quotation_invoice.pdf', $rendered['html'], $rendered['format']);
+  }
+
+  /**
+   * Renders the Invoice for the quotation linked to the contribution.
+   *
+   * @param int $contributionId
+   *   The contribution ID.
+   */
+  private function getContributionQuotationInvoice($contributionId) {
+    $salesOrder = Contribution::get()
+      ->addSelect('Opportunity_Details.Quotation')
+      ->addWhere('Opportunity_Details.Quotation', 'IS NOT EMPTY')
+      ->addWhere('id', '=', $contributionId)
+      ->addChain('salesOrder', CaseSalesOrder::get()
+        ->addWhere('id', '=', '$Opportunity_Details.Quotation')
+      )
+      ->execute()
+      ->first()['salesOrder'];
+
+    if (empty($salesOrder)) {
+      return;
+    }
+
+    /** @var \CRM_Civicase_Service_CaseSalesOrderInvoice */
+    $invoiceService = new \CRM_Civicase_Service_CaseSalesOrderInvoice(new CRM_Civicase_WorkflowMessage_SalesOrderInvoice());
+    return $invoiceService->render($salesOrder[0]['id']);
+  }
+
+  /**
+   * Determines if the hook will run.
+   *
+   * @param array $params
+   *   Mail parameters.
+   * @param string $context
+   *   Mail context.
+   * @param string $shouldAttachQuote
+   *   If the Attach Quote is set.
+   *
+   * @return bool
+   *   returns TRUE if hook should run, FALSE otherwise.
+   */
+  private function shouldRun(array $params, $context, $shouldAttachQuote) {
+    $component = $params['tplParams']['component'] ?? '';
+    if ($component !== 'contribute' || $context !== 'messageTemplate' || empty($shouldAttachQuote)) {
+      return FALSE;
+    }
+
+    return TRUE;
+  }
+
+}
diff --git a/CRM/Civicase/Service/CaseSalesOrderInvoice.php b/CRM/Civicase/Service/CaseSalesOrderInvoice.php
new file mode 100644
index 000000000..57dfa46a2
--- /dev/null
+++ b/CRM/Civicase/Service/CaseSalesOrderInvoice.php
@@ -0,0 +1,142 @@
+<?php
+
+use Civi\Api4\Address;
+use Civi\Api4\CaseSalesOrder;
+use Civi\Api4\CaseSalesOrderLine;
+use Civi\Api4\Contact;
+use Civi\Api4\Setting;
+use CRM_Civicase_WorkflowMessage_SalesOrderInvoice as SalesOrderInvoice;
+
+/**
+ * Renders sales order invoice.
+ */
+class CRM_Civicase_Service_CaseSalesOrderInvoice {
+
+  /**
+   * CreditNoteInvoiceService constructor.
+   *
+   * @param \CRM_Civicase_WorkflowMessage_SalesOrderInvoice $template
+   *   Workflow template.
+   */
+  public function __construct(private SalesOrderInvoice $template) {
+  }
+
+  /**
+   * Renders the sales order invoice message template.
+   *
+   * @param int $id
+   *   Sales Order ID.
+   *
+   * @return array
+   *   Rendered message, consistent of 'subject', 'text', 'html'
+   */
+  public function render(int $id) {
+    $caseSalesOrder = CaseSalesOrder::get()
+      ->addWhere('id', '=', $id)
+      ->addChain('items', CaseSalesOrderLine::get()
+        ->addWhere('sales_order_id', '=', '$id')
+        ->addSelect('*', 'product_id.name', 'financial_type_id.name')
+      )
+      ->addChain('computedRates', CaseSalesOrder::computeTotal()
+        ->setLineItems('$items')
+      )
+      ->addChain('client', Contact::get()
+        ->addWhere('id', '=', '$client_id'), 0
+      )
+      ->execute()
+      ->first();
+
+    if (!empty($caseSalesOrder['client_id'])) {
+      $caseSalesOrder['clientAddress'] = Address::get()
+        ->addSelect('*', 'country_id:label', 'state_province_id:label')
+        ->addWhere('contact_id', '=', $caseSalesOrder['client_id'])
+        ->execute()
+        ->first();
+      $caseSalesOrder['clientAddress']['country'] = $caseSalesOrder['clientAddress']['country_id:label'];
+      $caseSalesOrder['clientAddress']['state'] = $caseSalesOrder['clientAddress']['state_province_id:label'];
+    }
+
+    $caseSalesOrder['taxRates'] = $caseSalesOrder['computedRates'][0]['taxRates'] ?? [];
+    $caseSalesOrder['quotation_date'] = date('Y-m-d', strtotime($caseSalesOrder['quotation_date']));
+
+    $domain = CRM_Core_BAO_Domain::getDomain();
+    $organisation = Contact::get()
+      ->addSelect('image_URL')
+      ->addWhere('id', '=', $domain->contact_id)
+      ->execute()
+      ->first();
+
+    $model = new CRM_Civicase_WorkflowMessage_SalesOrderInvoice();
+    $terms = self::getTerms();
+    $model->setDomainLogo($organisation['image_URL']);
+    $model->setSalesOrder($caseSalesOrder);
+    $model->setTerms($terms);
+    $model->setSalesOrderId($id);
+    $model->setDomainLocation(self::getDomainLocation());
+    $model->setDomainName($domain->name ?? '');
+    $rendered = $model->renderTemplate();
+
+    $rendered['format'] = $rendered['format'] ?? self::defaultInvoiceFormat();
+
+    return $rendered;
+  }
+
+  /**
+   * Returns the Quotation invoice terms.
+   */
+  private static function getTerms() {
+    $terms = NULL;
+    $invoicing = Setting::get()
+      ->addSelect('invoicing')
+      ->execute()
+      ->first();
+
+    if (!empty($invoicing['value'])) {
+      $terms = Civi::settings()->get('quotations_notes');
+    }
+
+    return $terms;
+  }
+
+  /**
+   * Gets domain location.
+   *
+   * @return array
+   *   An array of address lines.
+   */
+  private static function getDomainLocation() {
+    $domain = CRM_Core_BAO_Domain::getDomain();
+    $locParams = ['contact_id' => $domain->contact_id];
+    $locationDefaults = CRM_Core_BAO_Location::getValues($locParams);
+    if (empty($locationDefaults['address'][1])) {
+      return [];
+    }
+    $stateProvinceId = $locationDefaults['address'][1]['state_province_id'] ?? NULL;
+    $stateProvinceAbbreviationDomain = !empty($stateProvinceId) ? CRM_Core_PseudoConstant::stateProvinceAbbreviation($stateProvinceId) : '';
+    $countryId = $locationDefaults['address'][1]['country_id'];
+    $countryDomain = !empty($countryId) ? CRM_Core_PseudoConstant::country($countryId) : '';
+
+    return [
+      'street_address' => CRM_Utils_Array::value('street_address', CRM_Utils_Array::value('1', $locationDefaults['address'])),
+      'supplemental_address_1' => CRM_Utils_Array::value('supplemental_address_1', CRM_Utils_Array::value('1', $locationDefaults['address'])),
+      'supplemental_address_2' => CRM_Utils_Array::value('supplemental_address_2', CRM_Utils_Array::value('1', $locationDefaults['address'])),
+      'supplemental_address_3' => CRM_Utils_Array::value('supplemental_address_3', CRM_Utils_Array::value('1', $locationDefaults['address'])),
+      'city' => CRM_Utils_Array::value('city', CRM_Utils_Array::value('1', $locationDefaults['address'])),
+      'postal_code' => CRM_Utils_Array::value('postal_code', CRM_Utils_Array::value('1', $locationDefaults['address'])),
+      'state' => $stateProvinceAbbreviationDomain,
+      'country' => $countryDomain,
+    ];
+  }
+
+  /**
+   * Returns the default format to use for Invoice.
+   */
+  private static function defaultInvoiceFormat() {
+    return [
+      'margin_top' => 10,
+      'margin_left' => 65,
+      'metric' => 'px',
+    ];
+  }
+
+}
diff --git a/civicase.php b/civicase.php
index 89ac2b026..88bc77c3b 100644
--- a/civicase.php
+++ b/civicase.php
@@ -189,6 +189,7 @@ function civicase_civicrm_buildForm($formName, &$form) {
     new CRM_Civicase_Hook_BuildForm_AddQuotationsNotesToContributionSettings(),
     new CRM_Civicase_Hook_BuildForm_AddSalesOrderLineItemsToContribution(),
     new CRM_Civicase_Hook_BuildForm_AddEntityReferenceToCustomField(),
+    new CRM_Civicase_Hook_BuildForm_AttachQuotationToInvoiceMail(),
   ];
 
   foreach ($hooks as $hook) {
@@ -556,6 +557,7 @@ function _civicase_add_case_category_case_type_entity(array &$entityTypes) {
 function civicase_civicrm_alterMailParams(&$params, $context) {
   $hooks = [
     new CRM_Civicase_Hook_alterMailParams_SubjectCaseTypeCategoryProcessor(),
+    new CRM_Civicase_Hook_alterMailParams_AttachQuotation(),
   ];
 
   foreach ($hooks as &$hook) {
diff --git a/templates/CRM/Civicase/Form/Contribute/AttachQuotation.tpl b/templates/CRM/Civicase/Form/Contribute/AttachQuotation.tpl
new file mode 100644
index 000000000..82a949091
--- /dev/null
+++ b/templates/CRM/Civicase/Form/Contribute/AttachQuotation.tpl
@@ -0,0 +1,14 @@
+<table>
+  <tr class="crm-email-element attach-quote">
+    <td class="label">{$form.attach_quote.label}</td>
+    <td class="html-adjust">{$form.attach_quote.html} <span>Yes</span></td>
+  </tr>
+</table>
+
+{literal}
+  <script type="text/javascript">
+    CRM.$(function ($) {
+      $('form.CRM_Contribute_Form_Task_Invoice > table.form-layout-compressed > tbody').append($('tr.attach-quote'))
+    })
+  </script>
+{/literal}