SELECT *
FROM
(
SELECT companyname, customers.customerid, COUNT(jobnumber) AS number_of_jobs FROM orders
	INNER JOIN customers ON customers.customerid = orders.customerid
WHERE (customers.group_company_id=1)
GROUP BY companyname, customers.customerid
) as x
GROUP BY LOWER(companyname)
HAVING COUNT(distinct x.customerid) > 1
ORDER BY companyname;