Just found this gem on the O2 website:
Text messaging abroad
Why write postcards when you can send a text? It's a low cost way of keeping in touch, and there are no charges to receive messages when you're abroad.
Just got to see what the cost if any it will cost me to send a text now! Otherwise I might have found a hidden goldmine, if I get to send them for free and Rizza gets to receive them for free.
But the following bit of info makes me think it might just be free for me:
Your Text messages abroad included in your domestic allowance
Pay Monthly customers can use text messages from within their normal text message allowance, at a rate of 4 to 1 i.e. you will use 4 normal text messages to send a text message from any where abroad.
A call to customer services is in order methinks
