diff --git a/CRM/Price/BAO/PriceSet.php b/CRM/Price/BAO/PriceSet.php
index 4f34f2243db6..f9e24c14d942 100644
--- a/CRM/Price/BAO/PriceSet.php
+++ b/CRM/Price/BAO/PriceSet.php
@@ -676,79 +676,7 @@ public static function processAmount($fields, &$params, &$lineItem, $priceSetID
         continue;
       }
 
-      switch ($field['html_type']) {
-        case 'Text':
-          $firstOption = reset($field['options']);
-          $params["price_{$id}"] = [$firstOption['id'] => $params["price_{$id}"]];
-          CRM_Price_BAO_LineItem::format($id, $params, $field, $lineItem, CRM_Utils_Array::value('partial_payment_total', $params));
-          $optionValueId = key($field['options']);
-
-          if (CRM_Utils_Array::value('name', $field['options'][$optionValueId]) === 'contribution_amount') {
-            $taxRates = CRM_Core_PseudoConstant::getTaxRates();
-            if (array_key_exists($params['financial_type_id'], $taxRates)) {
-              $field['options'][key($field['options'])]['tax_rate'] = $taxRates[$params['financial_type_id']];
-              $taxAmount = CRM_Contribute_BAO_Contribution_Utils::calculateTaxAmount($field['options'][$optionValueId]['amount'], $field['options'][$optionValueId]['tax_rate']);
-              $field['options'][$optionValueId]['tax_amount'] = round($taxAmount['tax_amount'], 2);
-            }
-          }
-          if (!empty($field['options'][$optionValueId]['tax_rate'])) {
-            $lineItem = self::setLineItem($field, $lineItem, $optionValueId, $totalTax);
-          }
-          $totalPrice += $lineItem[$firstOption['id']]['line_total'] + CRM_Utils_Array::value('tax_amount', $lineItem[key($field['options'])]);
-          break;
-
-        case 'Radio':
-          //special case if user select -none-
-          if ($params["price_{$id}"] <= 0) {
-            break;
-          }
-          $params["price_{$id}"] = [$params["price_{$id}"] => 1];
-          $optionValueId = CRM_Utils_Array::key(1, $params["price_{$id}"]);
-
-          // CRM-18701 Sometimes the amount in the price set is overridden by the amount on the form.
-          // This is notably the case with memberships and we need to put this amount
-          // on the line item rather than the calculated amount.
-          // This seems to only affect radio link items as that is the use case for the 'quick config'
-          // set up (which allows a free form field).
-          // @todo $priceSetID is a pseudoparam for permit override - we should stop passing it where we
-          // don't specifically need it & find a better way where we do.
-          $amount_override = NULL;
-
-          if ($priceSetID && count(self::filterPriceFieldsFromParams($priceSetID, $params)) === 1) {
-            $amount_override = CRM_Utils_Array::value('partial_payment_total', $params, CRM_Utils_Array::value('total_amount', $params));
-          }
-          CRM_Price_BAO_LineItem::format($id, $params, $field, $lineItem, $amount_override);
-          if (!empty($field['options'][$optionValueId]['tax_rate'])) {
-            $lineItem = self::setLineItem($field, $lineItem, $optionValueId, $totalTax);
-            if ($amount_override) {
-              $lineItem[$optionValueId]['line_total'] = $lineItem[$optionValueId]['unit_price'] = CRM_Utils_Rule::cleanMoney($lineItem[$optionValueId]['line_total'] - $lineItem[$optionValueId]['tax_amount']);
-            }
-          }
-          $totalPrice += $lineItem[$optionValueId]['line_total'] + CRM_Utils_Array::value('tax_amount', $lineItem[$optionValueId]);
-          break;
-
-        case 'Select':
-          $params["price_{$id}"] = [$params["price_{$id}"] => 1];
-          $optionValueId = CRM_Utils_Array::key(1, $params["price_{$id}"]);
-
-          CRM_Price_BAO_LineItem::format($id, $params, $field, $lineItem, CRM_Utils_Array::value('partial_payment_total', $params));
-          if (!empty($field['options'][$optionValueId]['tax_rate'])) {
-            $lineItem = self::setLineItem($field, $lineItem, $optionValueId, $totalTax);
-          }
-          $totalPrice += $lineItem[$optionValueId]['line_total'] + CRM_Utils_Array::value('tax_amount', $lineItem[$optionValueId]);
-          break;
-
-        case 'CheckBox':
-
-          CRM_Price_BAO_LineItem::format($id, $params, $field, $lineItem, CRM_Utils_Array::value('partial_payment_total', $params));
-          foreach ($params["price_{$id}"] as $optionId => $option) {
-            if (!empty($field['options'][$optionId]['tax_rate'])) {
-              $lineItem = self::setLineItem($field, $lineItem, $optionId, $totalTax);
-            }
-            $totalPrice += $lineItem[$optionId]['line_total'] + CRM_Utils_Array::value('tax_amount', $lineItem[$optionId]);
-          }
-          break;
-      }
+      list($params, $lineItem, $totalTax, $totalPrice) = self::getLine($params, $lineItem, $priceSetID, $field, $id, $totalPrice);
     }
 
     $amount_level = [];
@@ -1751,4 +1679,96 @@ protected static function reformatUsedByFormsWithEntityData($forms) {
     return $usedBy;
   }
 
+  /**
+   * Get the relevant line item.
+   *
+   * Note this is part of code being cleaned up / refactored & may change.
+   *
+   * @param array $params
+   * @param array $lineItem
+   * @param int $priceSetID
+   * @param array $field
+   * @param int $id
+   * @param float $totalPrice
+   *
+   * @return array
+   */
+  protected static function getLine(&$params, &$lineItem, $priceSetID, $field, $id, $totalPrice): array {
+    $totalTax = 0;
+    switch ($field['html_type']) {
+      case 'Text':
+        $firstOption = reset($field['options']);
+        $params["price_{$id}"] = [$firstOption['id'] => $params["price_{$id}"]];
+        CRM_Price_BAO_LineItem::format($id, $params, $field, $lineItem, CRM_Utils_Array::value('partial_payment_total', $params));
+        $optionValueId = key($field['options']);
+
+        if (CRM_Utils_Array::value('name', $field['options'][$optionValueId]) === 'contribution_amount') {
+          $taxRates = CRM_Core_PseudoConstant::getTaxRates();
+          if (array_key_exists($params['financial_type_id'], $taxRates)) {
+            $field['options'][key($field['options'])]['tax_rate'] = $taxRates[$params['financial_type_id']];
+            $taxAmount = CRM_Contribute_BAO_Contribution_Utils::calculateTaxAmount($field['options'][$optionValueId]['amount'], $field['options'][$optionValueId]['tax_rate']);
+            $field['options'][$optionValueId]['tax_amount'] = round($taxAmount['tax_amount'], 2);
+          }
+        }
+        if (!empty($field['options'][$optionValueId]['tax_rate'])) {
+          $lineItem = self::setLineItem($field, $lineItem, $optionValueId, $totalTax);
+        }
+        $totalPrice += $lineItem[$firstOption['id']]['line_total'] + CRM_Utils_Array::value('tax_amount', $lineItem[key($field['options'])]);
+        break;
+
+      case 'Radio':
+        //special case if user select -none-
+        if ($params["price_{$id}"] <= 0) {
+          break;
+        }
+        $params["price_{$id}"] = [$params["price_{$id}"] => 1];
+        $optionValueId = CRM_Utils_Array::key(1, $params["price_{$id}"]);
+
+        // CRM-18701 Sometimes the amount in the price set is overridden by the amount on the form.
+        // This is notably the case with memberships and we need to put this amount
+        // on the line item rather than the calculated amount.
+        // This seems to only affect radio link items as that is the use case for the 'quick config'
+        // set up (which allows a free form field).
+        // @todo $priceSetID is a pseudoparam for permit override - we should stop passing it where we
+        // don't specifically need it & find a better way where we do.
+        $amount_override = NULL;
+
+        if ($priceSetID && count(self::filterPriceFieldsFromParams($priceSetID, $params)) === 1) {
+          $amount_override = CRM_Utils_Array::value('partial_payment_total', $params, CRM_Utils_Array::value('total_amount', $params));
+        }
+        CRM_Price_BAO_LineItem::format($id, $params, $field, $lineItem, $amount_override);
+        if (!empty($field['options'][$optionValueId]['tax_rate'])) {
+          $lineItem = self::setLineItem($field, $lineItem, $optionValueId, $totalTax);
+          if ($amount_override) {
+            $lineItem[$optionValueId]['line_total'] = $lineItem[$optionValueId]['unit_price'] = CRM_Utils_Rule::cleanMoney($lineItem[$optionValueId]['line_total'] - $lineItem[$optionValueId]['tax_amount']);
+          }
+        }
+        $totalPrice += $lineItem[$optionValueId]['line_total'] + CRM_Utils_Array::value('tax_amount', $lineItem[$optionValueId]);
+        break;
+
+      case 'Select':
+        $params["price_{$id}"] = [$params["price_{$id}"] => 1];
+        $optionValueId = CRM_Utils_Array::key(1, $params["price_{$id}"]);
+
+        CRM_Price_BAO_LineItem::format($id, $params, $field, $lineItem, CRM_Utils_Array::value('partial_payment_total', $params));
+        if (!empty($field['options'][$optionValueId]['tax_rate'])) {
+          $lineItem = self::setLineItem($field, $lineItem, $optionValueId, $totalTax);
+        }
+        $totalPrice += $lineItem[$optionValueId]['line_total'] + CRM_Utils_Array::value('tax_amount', $lineItem[$optionValueId]);
+        break;
+
+      case 'CheckBox':
+
+        CRM_Price_BAO_LineItem::format($id, $params, $field, $lineItem, CRM_Utils_Array::value('partial_payment_total', $params));
+        foreach ($params["price_{$id}"] as $optionId => $option) {
+          if (!empty($field['options'][$optionId]['tax_rate'])) {
+            $lineItem = self::setLineItem($field, $lineItem, $optionId, $totalTax);
+          }
+          $totalPrice += $lineItem[$optionId]['line_total'] + CRM_Utils_Array::value('tax_amount', $lineItem[$optionId]);
+        }
+        break;
+    }
+    return [$params, $lineItem, $totalTax, $totalPrice];
+  }
+
 }
diff --git a/tests/phpunit/CRM/Event/Form/ParticipantTest.php b/tests/phpunit/CRM/Event/Form/ParticipantTest.php
index d142ddab3121..efa3efd53a5d 100644
--- a/tests/phpunit/CRM/Event/Form/ParticipantTest.php
+++ b/tests/phpunit/CRM/Event/Form/ParticipantTest.php
@@ -203,6 +203,24 @@ public function testSubmitWithPayment($thousandSeparator) {
     $contribution = $this->callAPISuccessGetSingle('Contribution', []);
     $this->assertEquals(1550.55, $contribution['total_amount']);
     $this->assertEquals('Debit Card', $contribution['payment_instrument']);
+    $lineItem = $this->callAPISuccessGetSingle('LineItem', []);
+    $expected = [
+      'contribution_id' => $contribution['id'],
+      'entity_table' => 'civicrm_participant',
+      'qty' => 1,
+      'label' => 'bug',
+      'unit_price' => 1550.55,
+      'line_total' => 1550.55,
+      'participant_count' => 0,
+      'price_field_id' => $this->_ids['price_field'][0],
+      'price_value_id' => $this->_ids['price_field_value'][1],
+      'tax_amount' => 0,
+      // Interestingly the financial_type_id set in this test is ignored but currently locking in what is happening with this test so setting to 'actual'
+      'financial_type_id' => CRM_Core_PseudoConstant::getKey('CRM_Contribute_BAO_Contribution', 'financial_type_id', 'Event fee')
+    ];
+    foreach ($expected as $key => $value) {
+      $this->assertEquals($value, $lineItem[$key]);
+    }
   }
 
   /**