You will receive an email confirmation with your order number, domain name or service and the price you paid, which you can use as your receipt. You can also look up the details of any transaction or any order in your Sydney ICT account:
Sign in to your Sydney ICT account
Choose Billing option under Profile menu in the bar at the top
Choose My Invoices
If you want to print or download your invoices you simple click on a line item and it will open for you.