Hi @noskurt,
you can release the number via “My o2” app, via o2 Community, via phone call or via chat. But a letter via mail is also possible.
Please have in mind that the mobile number portability is free of charge. To get your money back you can use this form: https://www.o2online.de/assets/blobs/pdfs/prepaid-guthabenauszahlung/
Kind regards,
Alex
18.07.2023 o2_Katja: Link aktualisiert
Hello @noskurt,
nice to have you with us in the community!
Has your concern been resolved in the meantime thanks to @MXP_Alex's help?
If you have any further questions or concerns, please do not hesitate to contact us.
Kind regards
Jessica