diff --git a/.gitignore b/.gitignore
index 86bd62d..1a7e9ad 100644
--- a/.gitignore
+++ b/.gitignore
@@ -10,3 +10,4 @@ docs/_build
 Pipfile
 Pipfile.lock
 lcov.info
+.vscode
diff --git a/sendsms/backends/smscsi.py b/sendsms/backends/smscsi.py
new file mode 100644
index 0000000..3cec095
--- /dev/null
+++ b/sendsms/backends/smscsi.py
@@ -0,0 +1,105 @@
+"""
+Configuration example
+---------------------
+
+settings.py:
+
+    SMS_CSI_BACKEND = 'sendsms.backends.smscsi.Csi'
+    SMS_CSI_USERNAME = 'xxxxxxxxxxxxx'
+    SMS_CSI_PASSWORD = 'xxxxxxxxxxxxx'
+    SMS_CSI_CODICE_PROGETTO = xxxxxx
+    SMS_CSI_PRIORITA = xxxxx
+    SMS_CSI_URL = 'xxxxxxxxxxxxxxxxx'
+
+"""
+import logging
+import requests
+import tempfile
+import xml.etree.ElementTree as ET
+
+from django.conf import settings
+
+from sendsms.backends.base import BaseSmsBackend
+
+logger = logging.getLogger(__name__)
+
+SMS_CSI_USERNAME = getattr(settings, 'SMS_CSI_USERNAME', '')
+SMS_CSI_PASSWORD = getattr(settings, 'SMS_CSI_PASSWORD', '')
+SMS_CSI_URL = getattr(settings, 'SMS_CSI_URL', '')
+SMS_CSI_CODICE_PROGETTO = getattr(settings, 'SMS_CSI_CODICE_PROGETTO', '')
+SMS_CSI_PRIORITA = getattr(settings, 'SMS_CSI_PRIORITA', '')
+
+
+class Csi(BaseSmsBackend):
+    
+    def send_messages(self, messages):
+        sent = 0
+        if not messages:
+            return sent
+        for message in messages:
+            try:
+                self._send(message)
+            except Exception as e:
+                if not self.fail_silently:
+                    raise e
+                else:
+                    logger.exception(str(e))
+            else:
+                sent += 1
+        return sent
+    
+    def _send(self, message):
+        if not self.is_valid(message.body):
+            return
+        recipients = ','.join(message.to).replace("+", "")
+        note = '-,' * len(message.to)
+        # remove last comma
+        note = note[:len(note) - 1]
+        xml_data = (
+            '<RICHIESTA_SMS>'
+            f'<USERNAME>{SMS_CSI_USERNAME}</USERNAME>'
+            f'<PASSWORD>{SMS_CSI_PASSWORD}</PASSWORD>'
+            f'<CODICE_PROGETTO>{SMS_CSI_CODICE_PROGETTO}</CODICE_PROGETTO>'
+            '<SMS>'
+            f'<TELEFONO>{recipients}</TELEFONO>'
+            f'<TESTO>{message.body}</TESTO>'
+            f'<PRIORITA>{SMS_CSI_PRIORITA}</PRIORITA>'
+            f'<NOTE>{note}</NOTE>'
+            '</SMS>'
+            '</RICHIESTA_SMS>'
+        )
+        logger.debug(f'Invio di sms: {message.body}')
+        xml = ET.ElementTree(ET.fromstring(xml_data))
+        with tempfile.TemporaryFile() as xml_file:
+            xml.write(xml_file)
+            xml_file.seek(0)
+            response = requests.post(
+                SMS_CSI_URL,
+                {'xmlSms': xml_file}
+            )
+        response_data = ET.fromstring(response.content)
+        if response.status_code != 200 or response_data[0].text == 'ERRORE':
+            error_message = (
+                f'Invio sms non riuscito, stato: {response.status_code}\n'
+                f'Contenuto della risposta: {response_data[1].text}'
+            )
+            self._raise_error(error_message)
+        logger.debug('Il messaggio è stato inviato con successo.')
+    
+    def is_valid(self, message):
+        length = len(message)
+        vowels = 'àáèéìíòóùúÀÁÈÉÌÍÒÓÙÚ'
+        for vowel in vowels:
+            if vowel in message:
+                length += 1
+        if length > 160:
+            error_message = 'La lunghezza del messaggio ha superato il lunghezza massima di 160.'
+            self._raise_error(error_message)
+            return False
+        return True
+    
+    def _raise_error(self, error_message):
+        if not self.fail_silently:
+            raise Exception(error_message)
+        else:
+            logger.exception(error_message)