Every autonomous or SME needs to manage and bill their business. To do this you simply need a program like Softonomo.
With Softonomo you have at your disposal an application, totally in English, that will allow you to manage everything related to each of your clients, suppliers, services, products, employed labor, etc. From the program interface you can make both budgets and delivery notes and invoices. It also allows you to manage all the income and expenses that are being produced, as well as keep track of profit and loss.
From the different Softonomo modules you can generate all kinds of listings, perform advanced searches by applying filters, make backup copies, save bank information, keep track of all tax concepts, VAT, IRPF, etc.
You can free download Softonomo 32, 64 bit and safe install the latest trial or new full version for Windows 10 from the official site.