As per my understanding, any post yr end credit notes issued LEADS TO REDUCTION in trade receivables balance at the year end BUT any post yr end cash receipts, DO NOT REDUCE trade receivables balance at the year end.
Credit note is adjusted only if it provides evidence that the amount should NOT be included in revenue/receivables at the y/e date – as we have described in detail many times.
Cash receipts provide confirmatory evidence that the customer OWED the debt – i.e. they OWED it – they were a DEBTOR. The debt was NOT settled at the reporting date – you cannot make it so retrospectively (!)