Did you remember to disable Find My iPhone before doing a factory reset?
If so, then it should be ready for a new owner. If your iPhone is Carrier Locked with Vodafone, it can only be used with a SIM card from that carrier. You must inform a new owner of this, alternatively you must have it unlocked.
To see if it's locked, set up the phone again and go to: Settings → General → About.
Under Carrier Lock, it says No SIM restrictions, so your iPhone is NOT locked to Vodaphone. If it says SIM Locked, your iPhone is locked to Vodafone.
You can see how to open your iPhone to other Carriers here:
How to unlock your iPhone for use with a different carrier - Apple Support
Also see this article, there is a lot of useful information on what to do before selling your iPhone.
What to do before you sell, give away, or trade in your iPhone or iPad - Apple Support