Keeping current sim and phone on a new contract

[wonderer99]

Guys I cant seem to see an answer anywhere for this.

Basically I have an older phone im happy with that uses a micro sim. My contract has run out so I can upgrade but newer phones I can choose from use nano sims. So my question is if I choose a new handset and plan does the new plan transfer to my current sim in my current phone so I can continue using that? I may keep the new phone as a spare, gift it or sell it, im undecided. 

The issue I fear is that the new plan will transfer to the nano sim and I will be forced to use the new phone as my older one only takes micro sim. I read that if the new phone has a different sim a new sim card needs to be used. But what if I want the upgrade but continue using my old sim and phone?  Hope that makes sense. 

Any advice would be apreciated.

[Nick_London]

OK, so if your contract has ended and you want to keep the same phone, why take out another phone contract if you don't really want it? 

Switch to a sim only deal which is so much cheaper,you may not even have to change the sim. 

[Geluk]

As you'd have found if you googled, all SIM's provided are capable of easy modification to one of the 3 sizes.