Am i ok to sell my phone?

A question about : Am i ok to sell my phone?

So i have 2 phones i have the iphone 6 (just upgraded) and my old s4 which i still like and use.

I am selling the iphone tommrow for Ј250 as i need to sell it asap to pay off a debit (i know you can get more but need it asap)

So am i allowed to sell the upgraded phone if i still pay the contract and use the sim in my s4?

Best answers:

• Thanks took it in to my local one and got Ј301
  thanks
• sure you can