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In most cases, you would just input the invoice into QuickFile. It’s not necessarily an actual invoice, but just a way of recording your income and VAT accurately. If it’s another system that’s generating the invoices, such as a till system or e-commerce site, then you can bulk record these, which should hopefully answer points 1, 2, 3 and 4. There’s more relating to bulk sales in these two topics:
Regarding point 5, QuickFile doesn’t support multiple styles of invoices as normal. You can create trading styles which allow you to have a number of different invoice templates, but this is tied to the client and not on an invoice-by-invoice basis. I have however included a link to this below for reference: