Invoice imports do not email customers. A Payment Date records an actual receipt.
1. Prepare the invoice file
Use Invoicing → Invoices → Import File and its sample. Check each invoice number, customer email, date, amount, and currency.
2. Use Payment Date only for money received
Include a Payment Date only when that amount was genuinely paid. It creates a payment and accounting effect on that date.
3. Handle partial receipts separately
A Payment Date with a positive Due Amount is rejected. Import that invoice without Payment Date, then use Manage Payments → Record payment for the actual partial receipt.
4. Check the imported history
Review the issued invoice and payment history. Confirm the date, paid amount, and balance. Do not send imported historical invoices merely to make their status look complete.