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

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.