I need to increment each new invoice id by 5, i have tried below code. But changed all invoices, shipments, orders and credit memos. I need each new invoice id increment by 5, shipments increment by 5 and credit memos increment by 3. Also sales order increment by 1(normal). How can i do this ?. Any one help me. class Mage_Eav_Model_Entity_Increment_Numeric extends Mage_Eav_Model_Entity_Increment_Abstract { public function getNextId() { $last = $this->getLastId(); if (strpos($last, $this->getPrefix()) === 0) { $last = (int)substr($last, strlen($this->getPrefix())); } else { $last = (int)$last; } $next = $last + 5; return $this->format($next); } }