Why do I get a notification about (€ 10) out-of-bundle usage?

As soon as you have out-of-bundle usage, we send you a notification because all of your usage from that point on will be charged on top of your regular bill. Each time you use € 10 out of bundle like that, we send you an email. You might get it a bit too early, though. Sorry!

Of course, you can always consult your account to check your out-of-bundle costs in detail in My Viking.