How do I restore a deleted customer?

I'll help you activate your customer, twisted3logistic.

The inactive customers are usually hidden from the customer list. To view and reactivate them, you'll have to turn on the Include inactive option. Here's how to do it:
 

1. Select Sales from the sidebar menu.
2. Go to the Customers tab.
3. Click the Gear icon above the Action column header.
4. Tick the Include inactive checkbox, then locate the name of your customer again.
5. Once you found it, select the Make active link from the Action column.

I've also added some articles that you can read to learn how to edit, import, and merge customers in QuickBooks Online: 

•  

  Add and manage customers

• Import customer list

Do you have any other questions in mind? Feel free to leave them below and I'll get back to you as soon as I can.