Show my caller id is greyed out y iPhone 6 plus. How can I rectify this? Your assistance is appreciated. Tx

Howdy noulliy,

I understand that you're not able to turn on Caller ID on your iPhone 6 plus. If you're using an iPhone that's on a CDMA network, then you'll need to contact your carrier for information on using Caller ID on your device. If you're on a GSM network, and still unable to enable or disable Caller ID in Settings > Phone, you'll need to contact your carrier for information regarding your plan's features.

Caller ID

Turn on or off in Settings > Phone.

Contact your carrier for information on using Caller ID.

iPhone: Understanding phone features - Apple Support

Cheers