Mobile roaming

[MatthewL]

Apologies but a new one for me and want some clarity in my head so I'm not stuck when I go.

 

I have 2 mobiles, one on EE and one on Smarty.  I am going to the Isle of Man and it comes under the roaming thing with mobiles (all new to me as never left the UK before or even own a passport!!) with EE it seems they text you and you reply and you buy a bundle as you cannot put it on your account before you go is that right?

 

With Smarty it appears I need to change some APN settings before I leave the UK but its not clear on how it works, has anyone roamed with Smarty before?

Want to know how it works as to which device I use as to what will be cheapest for me when I am there for the 4 days.  Any help would be appriciated.