You can use Authorize.Net for invoices for your business. The registration is FREE and when you register you will get 6 months free Ultimate invoicing subscription. When you register you can start using Billiving services and invoicing features. With this service you can create Professional PDF Invoices with Logo, send Automated late payment reminders, receive viewed invoice notifications, manage received payments, send automated due-date reminders. You can send invoice online and receive payment online. You will get unlimited invoicing free for up to 5 clients, forever. You can upgrade as your business grows. They also have fast, efficient customer service team.