I'm no Phone Geek, but the Sims have whatever Tariff  ( deal ) you are on; programmed on them. If you are "Pay as you go" then, for example, 25p for the first minute and 5p every minute thereafter. If you are on contract ( pay so much each month ) then so many free texts or calls and so much per minute thereafter, if you use up your allowance. My Daughter tells me mine went out with the Ark, but I tell Her I'm not the Idiot whose on facebook and Whatsapp etc. etc. that normally finishes the conversation.