Hi @Crisss,
Thanks for your post.
If you're looking to move to a SIM-only plan on your existing iD Mobile account and keep your current number, we'd recommend contacting our Sales Team for assistance.
They can review your account and advise on the available options to ensure you're making changes to your existing plan rather than taking out a separate new connection.
You can contact them via Live Chat here: https://www.idmobile.co.uk/live-chat
They'll be happy to help you find the right SIM-only option and avoid accidentally ending up with an additional SIM or mobile number.
Regards,
Gemma M
The iD Mobile Social Media Team