We sell different kind of products for cellphones stores, I would like to know which is the basic software in order to control all the customers and generate invoices for them
You may want to look into software such as inFlow Inventory if you're managing a bunch of products in multiple stores.
Not only will you be able to generate invoices for your customers, you'll be able to manage your vendors, create PO's and much more.
What you are looking for is an invoicing software solution. You can browse our Top 10 Invoicing Software report to find feature and pricing comparisons in order to discover the best solution for you.
One solution I recommend you give a look is Taulia, which should process invoices more efficiently, lower transaction cost and provide greater visibility for invoice creation and management. The solution is free for suppliers, so feel free to give it a try.
You can check Orderhive software to generate invoices & shipping labels. You can test the software by 15 days free sign up. You can easily control and track shipments in real-time.