Steps
- Login to Xero 
- Goto Contacts > Customers 
- Then click on New contact button in the top right corner. 
- Enter the required information 
- and hit Save & close button at bottom of the page 
- That's it. You have successfully added a new customer in Xero 
How to add customers in Xero?

Login to Xero
Goto Contacts > Customers
Then click on New contact button in the top right corner.
Enter the required information
and hit Save & close button at bottom of the page
That's it. You have successfully added a new customer in Xero