How can I retrieve missing Customers in my Sales list?

It's nice to see you here, @mkrohn,

If you accidentally make several customers inactive in your QBO account, you can restore them easily. To do that, follow the steps below:

1. Go to the Sales menu and choose Customers.
2. Tap the Gear icon above the Action column.
3. Make sure to click on the Include Inactive box.
   
4. Click the Gear again to close the preference and save the changes.
5. Find the customers that were made inactive and click on Make Active.
   

I'll be adding this article about managing customers for your reference: Make a customer inactive and then active

I hope this made your day better. If you need anything else, please tag me here. I'll be more than glad to assist you with QuickBooks. 

Thank you so much. That may have been what I did accidentally. I discovered a filter was set up somehow and I was able to clear it and all is good. I still have no idea how I did it though. 

Thank you for the quick response. Very helpful for future reference. Somehow I set a filter which I was able to clear and all is good now.

Good morning, @mkrohn. 

Thanks for reaching back out to the Community. I'm so glad we were able to help you with your customers' list within your QuickBooks Online (QBO) account. 

You can always check out our tutorials page for more details about other available features in the product. 

The Community is always here to have your back. If you have any other questions or concerns, don't hesitate to ask. I'm always here to lend a helping hand. Have a great weekend ahead!