I want to send a message to my mate who is on holiday. on http://www.cbfsms.com/ it says UK newtorks only, does that mean that despite him being on a UK network in england, he won't be on holiday (gran canaria). And on other SMS sites, it says put in country code before number, e.g. 447921 instead of 07921 for UK. If I send an SMS to him, do I put 44 in the front, or do I put in the code for gran canaria ?
Assuming that he has roaming enabled, there doesn't seem to be any reason why you cant send him a message. The fact that he is not in the UK at the time does not affect his phone number, so you use the international code for the UK (ie 44 followed by his number with first zero removed exactly as the example shown on their web site)