- # the sum of amount owed on all previous invoices
- $invoice_data{'previous_balance'} = sprintf("%.2f", $pr_total);
+ # the change in balance from that invoice to this one
+ $invoice_data{'balance_adjustments'} = sprintf("%.2f", ($self->previous_balance || 0) - ($self->billing_balance || 0) );
+
+ # the sum of amount owed on all previous invoices
+ # ($pr_total is used elsewhere but not as $previous_balance)
+ $invoice_data{'previous_balance'} = sprintf("%.2f", $pr_total);