diff --git a/admin_settings_invoice.php b/admin_settings_invoice.php
index 991e60fd4..d2b68f267 100644
--- a/admin_settings_invoice.php
+++ b/admin_settings_invoice.php
@@ -57,6 +57,16 @@
                     <small class="text-secondary">We recommend updating the invoice footer to include policies on your late charges. This will be applied every 30 days after the invoice Due Date.</small>
                 </div>
 
+                <div class="form-group">
+                    <label>Email address to notify when invoices are paid online <small class="text-secondary">(Ideally a distribution list/shared mailbox)</small></label>
+                    <div class="input-group">
+                        <div class="input-group-prepend">
+                            <span class="input-group-text"><i class="fa fa-fw fa-bell"></i></span>
+                        </div>
+                        <input type="email" class="form-control" name="config_invoice_paid_notification_email" placeholder="Address to notify for paid invoices, leave bank for none" value="<?php echo nullable_htmlentities($config_invoice_paid_notification_email); ?>">
+                    </div>
+                </div>
+
                 <hr>
 
                 <h4>Recurring Invoice</h4>
diff --git a/database_updates.php b/database_updates.php
index 1f9d22e77..6cbcd519c 100644
--- a/database_updates.php
+++ b/database_updates.php
@@ -2231,10 +2231,16 @@
         mysqli_query($mysqli, "UPDATE `settings` SET `config_current_database_version` = '1.5.2'");
     }
 
-    // if (CURRENT_DATABASE_VERSION == '1.5.2') {
-    //     // Insert queries here required to update to DB version 1.5.3
+     if (CURRENT_DATABASE_VERSION == '1.5.2') {
+         mysqli_query($mysqli, "ALTER TABLE `settings` ADD `config_invoice_paid_notification_email` VARCHAR(200) DEFAULT NULL AFTER `config_invoice_late_fee_percent`");
+
+         mysqli_query($mysqli, "UPDATE `settings` SET `config_current_database_version` = '1.5.3'");
+     }
+
+    // if (CURRENT_DATABASE_VERSION == '1.5.3') {
+    //     // Insert queries here required to update to DB version 1.5.4
     //     // Then, update the database to the next sequential version
-    //     mysqli_query($mysqli, "UPDATE `settings` SET `config_current_database_version` = '1.5.3'");
+    //     mysqli_query($mysqli, "UPDATE `settings` SET `config_current_database_version` = '1.5.4'");
     // }
 
 } else {
diff --git a/database_version.php b/database_version.php
index f61c2d695..16310497e 100644
--- a/database_version.php
+++ b/database_version.php
@@ -5,4 +5,4 @@
  * It is used in conjunction with database_updates.php
  */
 
-DEFINE("LATEST_DATABASE_VERSION", "1.5.2");
+DEFINE("LATEST_DATABASE_VERSION", "1.5.3");
diff --git a/db.sql b/db.sql
index 6686b3365..04568ef9f 100644
--- a/db.sql
+++ b/db.sql
@@ -1477,6 +1477,7 @@ CREATE TABLE `settings` (
   `config_invoice_from_email` varchar(200) DEFAULT NULL,
   `config_invoice_late_fee_enable` tinyint(1) NOT NULL DEFAULT 0,
   `config_invoice_late_fee_percent` decimal(5,2) NOT NULL DEFAULT 0.00,
+  `config_invoice_paid_notification_email` varchar(200) DEFAULT NULL,
   `config_recurring_prefix` varchar(200) DEFAULT NULL,
   `config_recurring_next_number` int(11) NOT NULL,
   `config_quote_prefix` varchar(200) DEFAULT NULL,
diff --git a/get_settings.php b/get_settings.php
index eda76869d..40f4cd35a 100644
--- a/get_settings.php
+++ b/get_settings.php
@@ -46,6 +46,7 @@
 $config_invoice_from_email = $row['config_invoice_from_email'];
 $config_invoice_late_fee_enable = intval($row['config_invoice_late_fee_enable']);
 $config_invoice_late_fee_percent = floatval($row['config_invoice_late_fee_percent']);
+$config_invoice_paid_notification_email = $row['config_invoice_paid_notification_email'];
 
 // Recurring Invoices
 $config_recurring_prefix = $row['config_recurring_prefix'];
diff --git a/guest_pay_invoice_stripe.php b/guest_pay_invoice_stripe.php
index c0a1b3079..0740e6b5e 100644
--- a/guest_pay_invoice_stripe.php
+++ b/guest_pay_invoice_stripe.php
@@ -306,6 +306,7 @@
     $config_smtp_password = $row['config_smtp_password'];
     $config_invoice_from_name = sanitizeInput($row['config_invoice_from_name']);
     $config_invoice_from_email = sanitizeInput($row['config_invoice_from_email']);
+    $config_invoice_paid_notification_email = sanitizeInput($row['config_invoice_paid_notification_email']);
     
     $config_base_url = sanitizeInput($config_base_url);
 
@@ -313,16 +314,33 @@
         $subject = "Payment Received - Invoice $invoice_prefix$invoice_number";
         $body = "Hello $contact_name,<br><br>We have received your payment in the amount of " . $pi_currency . $pi_amount_paid . " for invoice <a href=\'https://$config_base_url/guest_view_invoice.php?invoice_id=$invoice_id&url_key=$invoice_url_key\'>$invoice_prefix$invoice_number</a>. Please keep this email as a receipt for your records.<br><br>Amount: " . numfmt_format_currency($currency_format, $pi_amount_paid, $invoice_currency_code) . "<br>Balance: " . numfmt_format_currency($currency_format, '0', $invoice_currency_code) . "<br><br>Thank you for your business!<br><br><br>~<br>$company_name - Billing<br>$config_invoice_from_email<br>$company_phone";
 
-            $data = [
-                [
-                    'from' => $config_invoice_from_email,
-                    'from_name' => $config_invoice_from_name,
-                    'recipient' => $contact_email,
-                    'recipient_name' => $contact_name,
-                    'subject' => $subject,
-                    'body' => $body,
-                ]
+        $data = [
+            [
+                'from' => $config_invoice_from_email,
+                'from_name' => $config_invoice_from_name,
+                'recipient' => $contact_email,
+                'recipient_name' => $contact_name,
+                'subject' => $subject,
+                'body' => $body,
+            ]
+        ];
+
+
+        // Email the internal notification address too
+        if (!empty($config_invoice_paid_notification_email)) {
+            $subject = "Payment Received - $client_name - Invoice $invoice_prefix$invoice_number";
+            $body = "Hello, <br><br>This is a notification that an invoice has been paid in ITFlow. Below is a copy of the receipt sent to the client:-<br><br>--------<br><br>Hello $contact_name,<br><br>We have received your payment in the amount of " . $pi_currency . $pi_amount_paid . " for invoice <a href=\'https://$config_base_url/guest_view_invoice.php?invoice_id=$invoice_id&url_key=$invoice_url_key\'>$invoice_prefix$invoice_number</a>. Please keep this email as a receipt for your records.<br><br>Amount: " . numfmt_format_currency($currency_format, $pi_amount_paid, $invoice_currency_code) . "<br>Balance: " . numfmt_format_currency($currency_format, '0', $invoice_currency_code) . "<br><br>Thank you for your business!<br><br><br>~<br>$company_name - Billing<br>$config_invoice_from_email<br>$company_phone";
+
+            $data[] = [
+                'from' => $config_invoice_from_email,
+                'from_name' => $config_invoice_from_name,
+                'recipient' => $config_invoice_paid_notification_email,
+                'recipient_name' => $contact_name,
+                'subject' => $subject,
+                'body' => $body,
             ];
+        }
+
         $mail = addToMailQueue($mysqli, $data);
 
         // Email logging
diff --git a/post/admin/admin_settings_invoice.php b/post/admin/admin_settings_invoice.php
index fa3274d58..345017415 100644
--- a/post/admin/admin_settings_invoice.php
+++ b/post/admin/admin_settings_invoice.php
@@ -11,9 +11,13 @@
     $config_invoice_late_fee_percent = floatval($_POST['config_invoice_late_fee_percent']);
     $config_recurring_prefix = sanitizeInput($_POST['config_recurring_prefix']);
     $config_recurring_next_number = intval($_POST['config_recurring_next_number']);
+    $config_invoice_paid_notification_email = '';
+    if (filter_var($_POST['config_invoice_paid_notification_email'], FILTER_VALIDATE_EMAIL)) {
+        $config_invoice_paid_notification_email = sanitizeInput($_POST['config_invoice_paid_notification_email']);
+    }
 
 
-    mysqli_query($mysqli,"UPDATE settings SET config_invoice_prefix = '$config_invoice_prefix', config_invoice_next_number = $config_invoice_next_number, config_invoice_footer = '$config_invoice_footer', config_invoice_late_fee_enable = $config_invoice_late_fee_enable, config_invoice_late_fee_percent = $config_invoice_late_fee_percent, config_recurring_prefix = '$config_recurring_prefix', config_recurring_next_number = $config_recurring_next_number WHERE company_id = 1");
+    mysqli_query($mysqli,"UPDATE settings SET config_invoice_prefix = '$config_invoice_prefix', config_invoice_next_number = $config_invoice_next_number, config_invoice_footer = '$config_invoice_footer', config_invoice_late_fee_enable = $config_invoice_late_fee_enable, config_invoice_late_fee_percent = $config_invoice_late_fee_percent, config_invoice_paid_notification_email = '$config_invoice_paid_notification_email', config_recurring_prefix = '$config_recurring_prefix', config_recurring_next_number = $config_recurring_next_number WHERE company_id = 1");
 
     //Logging
     mysqli_query($mysqli,"INSERT INTO logs SET log_type = 'Settings', log_action = 'Edit', log_description = '$session_name edited invoice settings', log_ip = '$session_ip', log_user_agent = '$session_user_agent', log_user_id = $session_user_id");
diff --git a/post/admin/admin_settings_ticket.php b/post/admin/admin_settings_ticket.php
index 88ad7a3fe..724921841 100644
--- a/post/admin/admin_settings_ticket.php
+++ b/post/admin/admin_settings_ticket.php
@@ -8,7 +8,10 @@
     $config_ticket_email_parse_unknown_senders = intval($_POST['config_ticket_email_parse_unknown_senders']);
     $config_ticket_default_billable = intval($_POST['config_ticket_default_billable']);
     $config_ticket_autoclose_hours = intval($_POST['config_ticket_autoclose_hours']);
-    $config_ticket_new_ticket_notification_email = sanitizeInput($_POST['config_ticket_new_ticket_notification_email']);
+    $config_ticket_new_ticket_notification_email = '';
+    if (filter_var($_POST['config_ticket_new_ticket_notification_email'], FILTER_VALIDATE_EMAIL)) {
+        $config_ticket_new_ticket_notification_email = sanitizeInput($_POST['config_ticket_new_ticket_notification_email']);
+    }
 
     mysqli_query($mysqli,"UPDATE settings SET config_ticket_prefix = '$config_ticket_prefix', config_ticket_next_number = $config_ticket_next_number, config_ticket_email_parse = $config_ticket_email_parse, config_ticket_email_parse_unknown_senders = $config_ticket_email_parse_unknown_senders, config_ticket_autoclose_hours = $config_ticket_autoclose_hours, config_ticket_new_ticket_notification_email = '$config_ticket_new_ticket_notification_email', config_ticket_default_billable = $config_ticket_default_billable WHERE company_id = 1");