Here is an example of a Once Off sale and how it effects the General Ledger.
Sale
In this example it is an Account Sale
Cost: $ 1,000
Retail: $ 1,650 (Inc)
Receival
Goods are Received, then the Creditor Invoice is created.
Cost: $ 1,000
When the Once Off item is Received, it does the following postings:
When the Creditor Invoice is created, it posts the following:
POS Settings
It was using these POS settings