My customers that were saved on my create invoice have all disappeared

Welcome to the Community space, @dpanimal7574. We'll point you in the right direction to get this sorted so you can select or add a customer when creating and sending invoices inside QuickBooks Self-Employed (QBSE).

Before anything else, please know it isn't the experience we want you to have when utilizing the invoice feature of the program. We highly recommend contacting our Customer Care Team so they can access your account in a secure environment and conduct further investigation. This way, they can provide the necessary steps to troubleshoot this situation and restore the program to its default function so you can get back to creating an invoice and selecting customers for the transaction. We'll write down the steps to get you going:

1. Access your QuickBooks Self-Employed company.
2. On the top right corner, click the Help (?) and select Contact Us.
3. Enter “talk to a human”, then select Continue.
4. Select Have us call you or Chat with us to start a conversation with a support expert.

For more details, please see this page: Contact QuickBooks Self-Employed Support.

On the other hand, we're also providing this handy article to help you create personalized invoices for your customers inside the program: Create invoices in QuickBooks Self-Employed.

Please don't hesitate to comment below if you need our assistance with invoice-related duties or help performing specific tasks inside QuickBooks. We assure you that we'll be around to lend a helping hand as soon as possible. Keep safe.