diff --git a/api/src/Accounts.php b/api/src/Accounts.php
index 5c140dfe02..f9f6675aa4 100644
--- a/api/src/Accounts.php
+++ b/api/src/Accounts.php
@@ -212,7 +212,10 @@ class Accounts
 		if (empty($account_ids))
 		{
 			$account_ids = $hidden_account_ids;
-			if ($hidden === false) $account_ids[] = '!';
+			if ($hidden === false && $account_ids)
+			{
+				$account_ids[] = '!';
+			}
 		}
 		elseif ($hidden === true)
 		{
@@ -289,9 +292,10 @@ class Accounts
 		$serial = self::cacheKey($param, $serial_unlimited);
 
 		// implement $param['hidden'] via $param['account_id']
-		if (isset($param['hidden']) && !in_array($param['type'],['groups', 'owngroups']))
+		if (isset($param['hidden']) && !in_array($param['type'],['groups', 'owngroups']) &&
+			($account_id_filter = self::hidden2account_id($param['hidden'], (array)($param['account_id']??null))))
 		{
-			$param['account_id'] = self::hidden2account_id($param['hidden'], (array)$param['account_id']);
+			$param['account_id'] = $account_id_filter;
 		}
 		unset($param['hidden']);
 
diff --git a/api/src/Contacts/Sql.php b/api/src/Contacts/Sql.php
index 6b2cea3b9b..82ec97e7d9 100644
--- a/api/src/Contacts/Sql.php
+++ b/api/src/Contacts/Sql.php
@@ -719,6 +719,7 @@ class Sql extends Api\Storage
 		// implement negated account_id filter
 		if (!empty($filter['account_id']) && ($not_account_ids = array_search('!', $filter['account_id'])) !== false)
 		{
+			unset($filter['account_id'][$not_account_ids]);
 			$filter[] = $this->db->expression($this->table_name, ' NOT ', $this->table_name.'.', ['account_id' => $filter['account_id']]);
 			unset($filter['account_id']);
 		}
diff --git a/api/src/Contacts/Storage.php b/api/src/Contacts/Storage.php
index dbf4ae0b35..8a36b6308c 100755
--- a/api/src/Contacts/Storage.php
+++ b/api/src/Contacts/Storage.php
@@ -660,9 +660,10 @@ class Storage
 		//error_log(__METHOD__.'('.array2string($criteria,true).','.array2string($only_keys).",'$order_by','$extra_cols','$wildcard','$empty','$op',".array2string($start).','.array2string($filter,true).",'$join')");
 
 		// add hidden user filter for non-admins
-		if (empty($GLOBALS['egw_info']['user']['apps']['admin']) && empty($filter['owner']))
+		if (empty($GLOBALS['egw_info']['user']['apps']['admin']) && empty($filter['owner']) &&
+			($account_id_filter = Api\Accounts::hidden2account_id(false, $filter['account_id'] ?? null)))
 		{
-			$filter['account_id'] = Api\Accounts::hidden2account_id(false, $filter['account_id']);
+			$filter['account_id'] = $account_id_filter;
 		}
 		// Handle 'None' country option
 		if(is_array($filter) && isset($filter['adr_one_countrycode']) && $filter['adr_one_countrycode'] === '-custom-')