Hi, has anyone had problems with their customers not receiving invoices?

I won't rest until this is taken care of, @userinfo136. No worries, I have various troubleshooting steps here to help fix the problem.  

I want to make sure your customers are receiving their invoices. This way, they can review and pay their invoices at the soonest moment.

I'd recommend following the following troubleshooting steps below: 

1. Ensure that the customer's email in the invoice is correct so they can receive the transactions promptly. Do the following: 

      A. Go to the Invoices tab on the left pane. 

      B. Locate the invoice and click the Pencil icon. 

      C. Select Edit customer info and review the email. 

        2. If it's correct and the issue persists, I suggest you to delete the invoice, then create and send it again. There's a possibility that the sales form is corrupted. See the sample screenshot below for your reference: 

        3. If the issue continues, let them check their junk or spam folder. 

        4. If problem persevere, let your customer open their email through incognito. Then if it's fixed, let them go back to their regular browser and clear their cache. 

        5. If there's no progress, let your customer use another email. 

Visit these articles below to learn more about managing invoice and another QuickBooks Self-Employed topics: 

• Help Articles. 
• Create invoices in QuickBooks Self-Employed

If you're in over your head with QuickBooks invoices, don't hesitate to drop me a line. I'm here for you, and I'll be happy to help again. Take care.