Within Teamwork Desk you can find all of the invoices for your subscription and payments details in the billing section

To view these  click on your profile icon to the top right of the navigation bar and select 'Settings':

Near the top of the page select the 'Billing' area of settings:

Within the left pane select "Billing History":

From here, all payment details can be viewed at a glance or a more detailed view can be accessed by clicking on "View Invoice", at the end of each row. 

When an invoice is viewed, an option to download a copy is also presented.

Note: Only administrators will have access to this area.