Goodybags are not valid in the Republic of Ireland, you will be on EU roaming rates.
It's 45p/MB for data, so will cost a lot to use. See http://giffgaff.com/index/international for full list of rates.
You're better off seeking out free wifi for data use.
I'm going to the Republic of Ireland in a couple of weeks time, can I use my mobile over there to text and call people back in England England, also can I still use my whatsapp over there aswell
you will be able to use your phone in ROI just as you do now.
However, your goodybag will not work and you would therefore need credit on your phone to text, make calls and to go on the internet.
the excat costs of using your phone will be:
|Dialling within EU and select countries plus calls to voicemail (charged in per second increments after first 30 seconds) this includes calling back to UK||24p per minute|
|Dialling outside this price band -||£1 per minute|
|Receiving calls (charged in per second increments)||7p per minute|
|Sending texts||8p per text|
|Picture messages (MMS) to a UK mobile||16p per MMS|
|Picture messages (MMS) to any other mobile||24p per MMS|
|Data Roaming*||45p per MB|
key thing to remember is that you will be charged for receiving calls and cost of using your internet will be high. So try and make best use of free wifi hotspots in cafes and hotel etc
hope this helps