diff --git a/myaccount/register_instance.php b/myaccount/register_instance.php
index 79eebb77b..22ad461f8 100644
--- a/myaccount/register_instance.php
+++ b/myaccount/register_instance.php
@@ -1150,7 +1150,14 @@
 	if (! empty($conf->global->SELLYOURSAAS_DEFAULT_CUSTOMER_CATEG)) {
 		dol_syslog("register_instance.php We will set customer into the categroy");
 
-		$result = $tmpthirdparty->setCategories(array($conf->global->SELLYOURSAAS_DEFAULT_CUSTOMER_CATEG => $conf->global->SELLYOURSAAS_DEFAULT_CUSTOMER_CATEG), 'customer');
+		// To prevent deletion of categories already present
+		$categories =  $tmpthirdparty->getCategoriesCommon('customer');
+		$arraycateg = array($conf->global->SELLYOURSAAS_DEFAULT_CUSTOMER_CATEG => $conf->global->SELLYOURSAAS_DEFAULT_CUSTOMER_CATEG);
+		if (is_array($categories) && !in_array($conf->global->SELLYOURSAAS_DEFAULT_CUSTOMER_CATEG, $categories)){
+			$categories = array_merge($categories, $arraycateg);
+		}
+
+		$result = $tmpthirdparty->setCategories($categories, 'customer');
 		if ($result < 0) {
 			$db->rollback();