Hello Rrrr
Thank you for your message.
Normally you will receive the invoice for renewal 2 months before expiry. (Except if you have a temporary residence or have cancelled the travelcard).
If the renewal takes place before your 25th birthday, you will pay the youth price for another year.
You can see the travelcard information in your SwissPass account and the invoice 2 months before the renewal.
Have a nice day.
Greetings TatianaR