XING Help Center
Here you’ll find answers to your questions, and information about XING features. You can also contact the XING Support team (available in English and German) if you need any other assistance.
By the way, we've published some help videos that may be of use to you: Go to videos
Are invoices digitally signed?
All invoices are digitally signed and available in your account by going to "Home" → "Invoices & Accounts" → "Invoices".