New iphone: Will I lose all my messages / contacts?

[nowwearefour]

I have a new iPhone with the same number but new sim. I am scared that when inactivate new sim the old messages will go ( I have some special ones I don't want to lose). Help!!!

Sync the old phone with your computer before you swap to the new one. I think everything should then be there when you activate the new one. I think you can restore the new iPhone from the last sync- does that make sense?

Mine was all synched to the cloud, kept all messages etc.

Oooh ok. Tricky thing is that this time I want to use my husbands iTunes account on my new phone, can I do that? Will it make a difference?