A:AnswerDon't really need to put anything down on the new phone. Check with your Service Provider to see what other offer they may have. Hope this helps.
A:AnswerYes you can. If your husbands iphone 4 is backed up on your computer or Mac (or iCloud), you would reset your iPhone 6 to factory settings. You would then insert your husbands SIM card into your iPhone 6. You would then restore your iPhone 6 to your husbands backup of his iPhone 4 (through your computer, Mac, or iCloud). Hope this helps :-)