diff --git a/htdocs/fichinter/fiche.php b/htdocs/fichinter/fiche.php
index 4f6cf6d5744..1b0e8351c96 100644
--- a/htdocs/fichinter/fiche.php
+++ b/htdocs/fichinter/fiche.php
@@ -166,7 +166,18 @@ if ($_GET["action"] == 'create')
 
 	print "<input type=\"hidden\" name=\"action\" value=\"add\">";
 
-	print "<tr><td>".$langs->trans("Ref")."</td><td><input name=\"ref\" value=\"$numpr\"></td></tr>\n";
+	print "<tr><td>".$langs->trans("Ref")."</td>";
+	
+	// en attendant le module de numérotation
+	if ($societe->prefix_comm)
+	{
+		print "<td><input name=\"ref\" value=\"$numpr\"></td></tr>\n";
+	}
+	else
+	{
+		print "<td>".$langs->trans("CustomerDoesNotHavePrefix")."</td></tr>\n";
+	}
+	
 	print "<tr><td>".$langs->trans("Duration")." (".$langs->trans("days").")</td><td><input name=\"duree\"></td></tr>\n";
 
 	if ($conf->projet->enabled)
@@ -199,7 +210,7 @@ if ($_GET["action"] == 'create')
 
 			$user->getrights("projet");
 
-			if ($user->rights->projet->creer)
+			if ($user->rights->projet->creer && $societe->prefix_comm)
 			{
 				print '<a href='.DOL_URL_ROOT.'/projet/fiche.php?socidp='.$socidp.'&action=create>'.$langs->trans("Add").'</a>';
 			}
diff --git a/htdocs/langs/en_US/interventions.lang b/htdocs/langs/en_US/interventions.lang
index 9213b2a4eba..7552911e411 100644
--- a/htdocs/langs/en_US/interventions.lang
+++ b/htdocs/langs/en_US/interventions.lang
@@ -8,4 +8,5 @@ AddIntervention=Add intervention
 ListOfInterventions=List of interventions
 LastInterventions=Last %s interventions
 AllInterventions=All interventions
-CreateDaftIntervention=Create draft
\ No newline at end of file
+CreateDaftIntervention=Create draft
+CustomerDoesNotHavePrefix=Customer does not have a prefix
\ No newline at end of file
diff --git a/htdocs/langs/fr_FR/interventions.lang b/htdocs/langs/fr_FR/interventions.lang
index d38960d3ba1..03e9b19cd8e 100644
--- a/htdocs/langs/fr_FR/interventions.lang
+++ b/htdocs/langs/fr_FR/interventions.lang
@@ -8,4 +8,5 @@ ListOfInterventions=Liste des interventions
 EditIntervention=Editer
 LastInterventions=Les %s dernières interventions
 AllInterventions=Toutes les interventions
-CreateDaftIntervention=Créer brouillon
\ No newline at end of file
+CreateDaftIntervention=Créer brouillon
+CustomerDoesNotHavePrefix=Le client n'a pas de préfixe de défini
\ No newline at end of file