An invoice number already used in the selected business is skipped rather than updated.
1. Check the current records
Select the business and review Invoicing → Invoices for the numbers already present. Separate genuine new sales from documents you already imported.
2. Prepare the new invoices
Open the invoice import and use its sample. Include Customer Name, an eligible Customer Email, Invoice No, dates, currency, amounts, and the required item columns.
3. Keep each sale together
Place the rows for one new invoice number together. They become the lines of that invoice. Do not give every product its own invoice number.
4. Import and inspect
Apply the reviewed file and read the result. Check created invoices and skipped reasons. Do not rename an existing sale merely to bypass a duplicate-number refusal.