To modify the Invoice after it has been paid

Hi @QFMathew
You mean I can delete the Credit note, modify the invoice, then make a new credit note for another value and send to the client for payment, right?
Youre right, we are VAT registered, Ive just started trading and made only one Nill VAT report yet, the next period I have 1 year, ends this month. I`ve planned to report by fact debited and credited amount. Your suggestions are very valuable for me at this stage. We have a small number of clients and invoices per year, all of them are importing goods and selling in UK.
About the invoicing approaches: first and second of your mentioned are more relevant for us, as we are supplying goods and can not divide same goods batch into several invoices.
Please suggest how to tag payments? This might help a lot.
Does the approach of updating the credit note several times for the same invoice work as well? To make each next payment possible. I thought about: 1) make Invoice and Credit note 70% - the client pays 30%, 2) the next stage - modify Credit note to 30% - the client pays his next 40% of the Invoice, and 3) delete Credit note to let the client pay the rest 30% of the invoice