I have a SIM is on a one year contract with BT. It was a good deal with Quidco cashback and some Amazon vouchers as a reward I think I ended up getting back nearly all of the £10 per month fee 
The contract is up in a few weeks and I was thinking about asking BT what deals they can offer to renew my contract. However, it then occurred to me that it might be better just to order a brand new SIM and presumably qualify for cashback and reward vouchers again. The phone is only used for data, so changing the number isn't a big deal. Is there a flaw in this plan that I'm not spotting?

The contract is up in a few weeks and I was thinking about asking BT what deals they can offer to renew my contract. However, it then occurred to me that it might be better just to order a brand new SIM and presumably qualify for cashback and reward vouchers again. The phone is only used for data, so changing the number isn't a big deal. Is there a flaw in this plan that I'm not spotting?