Within Teamwork Projects, you can find all of the invoices for your subscription and details of the payments made in the subscription area of the site settings menu
To view these, select 'Settings' to the top right of your screen, and click Subscription:
Note: Only site administrators in the owner company will have access to this area.
On the subscription screen, you will see an 'Invoices' button, clicking this will bring you to a list of your payments and links to download your invoices.
For more information see: Upgrading your Teamwork Projects plan