Is 3G free on iPhone 4s payasyougo?

My phone came with 3G turned on and I'm not sure if it's free or if it's running up a bill, I have disabled it at the moment but it would be great if I could use it and not have to pay. Cheers

I don't know

3g is the speed of internet data your phone gets and doesn't involve voice calls if you use the phone for internet use you need to have a data on your payment plan weather payg or contract phone you will have the amounts of

min/talktime
texts
data(will be in Mb or gigs)

if you don't subscribe to a bundle or plan with data you will pay hefty for any internet you use.

3G & 4G are the same for payment, if you pay, you pay for both…

You are only charged once for the calls you make or the data you use, leave it on because if you travel to an area outside of your carriers 4G network, it will automatically switch over to 3G until you get within range of 4G again.