Maybe someone can advise. I am beginning to sell at craft fairs using a card machine (izettle) and have already experienced coverage issues with 3 at RHS Wisley. I need a reliable method of taking payments at these places and wondered how to do. other places include RHS Hyde Hall and Blenheim Palace. does the new roaming laws give n an option, do I have to have 4 phones and 4 network providers? help would be most appreciated. of course I need as cheaply as possible, I don't need to make calls not texts and it is fairly low internet usage.