How to viber from an old iPhone to new iPhone?

I got a new iPhone 5S, I have viber on iPhone 4.
I register viber on iPhone 4 with my phone number, now I want to use viber on iPhone 5S with my phone number.
How can I do it?!
I mean how can I use viber on new phone with a phone number that I registered once before?
Can I register two phones with one number?

GFGS

Activate Iphone 5s… Download viber onto the new iphone 5s… Sell Iphone 4 cause you will no longer be needing it… Drink a beer… Enjoy

You have to do the following on iPhone 4

In Viber
1. Open Viber
2. More Tab
3. Deactivate Account

Now on iPhone 5S
1. Get Viber
2. Register with Viber

  • Why did vodafone charge my iphone viber calls? I'm using my iphone 3 given to me by my sister in HK. I insert a contract vodafone sim card in this phone and everything works ok, except for the viber calls. Vodafone charged me about £50 for a 45-min call recently. They insisted that it was an international call and not a viber call! Now I dare not use the viber apps anymore. I don't know if the phone had been locked in HK but I didn't have to unlock it in order to use my vodafone sim card with it.
  • Whatsapp and Viber on Iphone? I'm getting an iphone 3gs that is of 8gb. I'm going to install whatsapp and viber on it and I was wondering if i need any kind of data plan or package or if i can use them both using just the Wi-Fi at home? Will they work properly if they are running on just the Wi-Fi and will I need any kind of plan at all to use them or will I be charged for the internet usage?
  • Viber messaging app for iPhone/android? I've got a couple of questions: If I have an iPhone and someone has an android, will it still work? Also, if I'm in the UK and she is in Ireland, should that work? If it should, then it isn't. Anything I can do?
  • Using Viber on iPhone with Wi-Fi in different country? Hi so I'm traveling next week and I was wondering if it will be free to use Viber from my iPhone using Wi-Fi. If I'm connected to Wi-Fi will I be charged/ will it work in a different country. I'm going to America if that matters.