iphone 5s sim to 6s any worries?

[Zombiecrowd]

To keep my unlimited data I am doing the forever method basically transferring my upgrade on UDP line to a 2GB line and activating the new 6s on that line. I was going to switch sim cards after that to get my UDP line on the new 6s.

But I read in a few places if I keep my sim from my current 5s and put it in the new 6s I cannot take advantage of the new LTE speeds. I thought the new upgrades were part of the modem upgrade in the phones and had nothing to do with the sim card.

Can anyone confirm that keeping my 5s sim and putting it in the new 6s phone is 100% OK and not a downgrade in speed? Verizon if this matters

 

[ldpm14]

I can confirm that it will work. The iPhone 5s and the 6s both use the nano sim card. Just make sure you update the new phones IMEI/ESN with your carrier.

 

[Lobwedgephil]

Just switch sims before you power on and you will be fine.

 

[Cergman]

I don't think you get HD Voice with the old SIMs tho. When I moved my sim from my 5s (from my 5) to my 6, AT&T notified me that I needed a new sim for HD Voice.

 

[Zombiecrowd]

Is HD voice the only thing?