Thanks a lot for the response. I had that initially and I thought that was causing the problem. I changed the Mode of Payments to the following:
Cash = Cash
Online Transfer = Bank
Credit Card = Bank
This is the process I went through:
Run the POS
Create a new user, fill in the name, address, phone number, email address
Add item to cart
Checkout
POS Invoice gets generated fine until here. (POS invoice ACC-PSINV-2021-00001 created succesfully). The status is still “unpaid” though at this stage. I can print the POS Invoice and give it to customer. Up to this point, it has always worked wonders.
When I close the POS, it still throws me the same error. (Sales Invoice ACC-SINV-2021-00001: Customer is required against Receivable account Jerung Wheels Sales - JWE)
So I went into the new customer, added a row into the accounting that points to the “36025489 - Retail Shop Sales - JWE”
I tried going again to to the POS Closing, still the same error.
Thank you @Suresh_Thakor for the assistance! The main problem was, the POS should be using Income account rather than Receivable account. The receivable account only needs to be defined in the Company’s default receivable account.