Whenever you confirm a payment/transfer you'll see a lodgement number and a receipt number. The receipt number confirms that the payment has been submitted successfully.
For scheduled payments, you can check the status and the receipt number via "View past Payments/Transfers" from the "Payments" menu. For unsuccessful payments, the status will show as failed. You can also check the details of the payment to find the reason the payment failed.
Find out more about past payments and transfers: