How do I identify unknown charges?

Can you turn off the Premium features option in your iD account online @Jack Ingram?

Have you tried sending an SMS with “STOP” to 85004?
Doing this should stop the premium rate messages being sent to your handset. 
🤞

Hi @Jack Ingram 

iD Mobile is not able to provide a refund for these charges as the text subscriptions are signed up to from the user end and not by the network.

We're unable to stop these or unsubscribe you to these from our end. In most cases, you will need to text STOP to the number to stop the subscription. Doing so may incur a further charge for sending the text, however, it should stop any further communication from them.

If you did not sign up to this subscription yourself and believe you have been scammed, we'd urge you to first contact the company directly to obtain a refund (and be removed from their mailing lists).

There's a regulatory body called the Phone-paid Services Authority (PSA) who regulate these companies. You can use their website at https://psauthority.org.uk to locate the information about the company. If you've already contacted the company and failed to retrieve a resolution, you can make a complaint via PSA directly. 

Please also see the following article which refers to this type of situation: https://www.which.co.uk/consumer-rights/advice/im-being-charged-for-unwanted-premium-rate-text-messages it may provide some further insight into these types of subscriptions.

Tom