I recently bought a 10 £ goody bag I still didn't activate it. I have no idea when it expires how to find that out
It expires one calendar month AFTER activation.
Do you meen you bought a voucher but havnt activated it yet.
If you got a monthly package then you can see the details https://giffgaff.com/dashboard
If you got a voucher, then the expiry would be on the voucher receipt.
You can message an agent to find out if it's active https://support2.giffgaff.com/app/ask/Top-up-balances-and-goodybags/Using-a-top-up-voucher/