Hallo, 

I have the Magenta prepaid card S for with the 1 Gb tarif monthly (4.95 euros).  I am leaving Germany definitively and may come back from time to time. However, I would like to keep my cell phone number with me to use it in Europe when I come back. For this, I would like to change the monthly tarif.  When I top up 15 euros with the app, it will still charge me every month. Can I charge internet just when I am in Germany without paying monthly?