Upgrading to sim only

[Nicksd26]

My current contract ends in the coming days and I’m looking to keep my phone so im looking to just get a sim only contract. When I get to the checkout with the plan I want it is saying it’s a multi sim which would imply I’m just adding another sim to my account which I do not want, i just want upgrade/ update my current plan.
Can you advise if I where to confirm this plan that it will just update my current sim when my current contract ends or will it add another sim to my account and another sim will be sent out? 

[bristolian]

If you have followed the "upgrade now" options on the website, then your plan will be updated on your minimum term end date, and there is no reason to replace a perfectly working SIM.

If you're not sure, then contacting CS on 150 will also suffice, you can ask for a priceplan change effective from the relevant date.