diff --git a/data/schema.sql b/data/schema.sql
index 37097b9..0cc7a67 100644
--- a/data/schema.sql
+++ b/data/schema.sql
@@ -21,7 +21,7 @@ CREATE TABLE IF NOT EXISTS plugin_facturation_clients (
 	adresse				TEXT NOT NULL,
 	code_postal			TEXT NOT NULL,
 	ville				TEXT NOT NULL,
-    siret               TEXT NOT NULL,
+    siret               TEXT,
 	date_creation		TEXT NOT NULL DEFAULT CURRENT_DATE CHECK (date(date_creation) IS NOT NULL AND date(date_creation) = date_creation), -- Date d\'inscription
 	telephone			TEXT,
 	email				TEXT
diff --git a/lib/Client.php b/lib/Client.php
index e1bd682..66aabf3 100644
--- a/lib/Client.php
+++ b/lib/Client.php
@@ -40,7 +40,7 @@ class Client
 			{
 				$data[$key] = trim($data[$key]);
 
-				if($data[$key] == '' && ($key != 'telephone' && $key != 'email'))
+				if($data[$key] == '' && ($key != 'siret' && $key != 'telephone' && $key != 'email'))
 				{
 					throw new UserException('Le champs '.$key.' doit être renseigné.');
 				}
@@ -128,7 +128,7 @@ class Client
 				'label' => 'Ville',
 			],
             'siret' => [
-                'label' => 'Siret',
+                'label' => 'SIRET',
             ],
 			'telephone' => [
 				'label' => 'Téléphone',
diff --git a/templates/client_modifier.tpl b/templates/client_modifier.tpl
index 08f16aa..42e6f1c 100644
--- a/templates/client_modifier.tpl
+++ b/templates/client_modifier.tpl
@@ -11,7 +11,7 @@
             {input type="text" name="adresse" label="Adresse" required=true source=$client}
             {input type="text" name="code_postal" label="Code postal" required=true source=$client}
             {input type="text" name="ville" label="Ville" required=true source=$client}
-            {input type="text" name="siret" label="SIREN/SIRET" required=true source=$client}
+            {input type="text" name="siret" label="SIREN/SIRET" source=$client}
             {input type="tel" name="telephone" label="Téléphone" source=$client}
             {input type="email" name="email" label="Adresse e-mail" source=$client}
         </dl>
diff --git a/templates/clients.tpl b/templates/clients.tpl
index 47ccce2..306b044 100644
--- a/templates/clients.tpl
+++ b/templates/clients.tpl
@@ -55,7 +55,7 @@
             {input type="text" name="adresse" label="Adresse" required=true}
             {input type="text" name="code_postal" label="Code postal" required=true}
             {input type="text" name="ville" label="Ville" required=true}
-            {input type="text" name="siret" label="SIREN/SIRET" required=true}
+            {input type="text" name="siret" label="SIREN/SIRET"}
             {input type="tel" name="telephone" label="Téléphone"}
             {input type="email" name="email" label="Adresse e-mail"}
         </dl>
diff --git a/upgrade.php b/upgrade.php
index 6cd4ff5..5df22ea 100644
--- a/upgrade.php
+++ b/upgrade.php
@@ -222,7 +222,7 @@ if (version_compare($old_version, '0.8.5', '<'))
                   adresse			TEXT NOT NULL,
                   code_postal		TEXT NOT NULL,
                   ville				TEXT NOT NULL,
-                  siret             TEXT NOT NULL,
+                  siret             TEXT,
                   date_creation		TEXT NOT NULL DEFAULT CURRENT_DATE CHECK (date(date_creation) IS NOT NULL AND date(date_creation) = date_creation),
                   telephone			TEXT,
                   email				TEXT
@@ -233,7 +233,6 @@ if (version_compare($old_version, '0.8.5', '<'))
     $sql = 'SELECT * FROM plugin_facturation_clients';
     foreach ($db->iterate($sql) as $client)
     {
-        $client->siret = "";
         $db->insert('plugin_facturation_clients_tmp', $client);
     }
     // remplacer l'ancienne table par la nouvelle