hI ALL
Same as above. Do companies using NGN' have to advertise call prices per minute or is that just for premium numbers????

Simply answered, NO !  ::)

It depends.  As DaveM says, simply no but in adverts (except TV, internet and Radio) they are meant to provide a general guide of how much the call costs from a BT landline.

For example, an organisation using an 0871 in and advert within the local paper should state something along the lines, "calls cost upto 10p/min from a BT landline.  Costs from other networks may vary"

This is because different telephone companies are allowed to charge pretty much what they like and so as a guide only they use costs from a BT landline.

In reality, however, very few organisations even in their adverts state the cost of calls to 084x/087x numbers.  Possibly because they're not aware they have to but mostly because it's not in their interests (ie possibly bad for business) to do so.