Hi!

o2 prepaid does not offer the option to reset the data volume when the high-speed data volume is exhausted.

But o2 offers these different options:
*Add additional data volume to your smartphone options. Example: If you are already using the o2 my Prepaid S / M or L package, you can add 400 MB / 800 MB / 2 GB / 4 GB data volume if you book one of the data packages DATA PACK S / M / L or XL.
Remember: Both packages will be renewed automatically if your balance is sufficient. If you no longer want to use the additional pack, you must cancel it.

*You can book a Surf On in Mein o2 or in the Mein o2 app until the end of the booked package. The package ends automatically.

*You can also end the booked package immediately and then re-book it immediately.

Note: From February 11th, o2 will renew the prepaid options. For example, instead of 1.5 GB high-speed data volume, the o2 my Prepaid S has 3.5 GB and the price remains at 9.99 euros.

Thanks a lot for the answer, but I could not find the option in Mein O2 app.

Could you please let me know how to access these options? I can only find general recharge options at this website: https://prepaid-aufladung.o2online.de/

With this link you can top up your credit.

You can choose options here: https://www.o2online.de/ecare-prepaid/tarifdetails