How to stop negative stock

in my business selling negative stock makes bad customer relations, if my sales raise items not in stock ,that bring bad reputation for my business, i want to stop negative sales, is there a way i can block negative sales in my system, i am considering going on cloud, will have my sales team remotely making sales invoices, if i don’t have control over sales QTY it will be big problem for my business, invoice QTY cannot be delivered