Firstly, just go to your email. Your order confirmation email is a Tax Invoice.
Or, login to the site, select Order Status, then click on the View order button next to the relevant order (picture of an eye). At the bottom of this page, simply press the button labelled Print Invoice.
If you're still having trouble getting your invoice, simply fill in our online contact form and remember to include your order number. Our team will send you a copy of your invoice in a PDF as soon as possible.