For most engineer visits, there's no charge. For instance, the call out charge doesn't apply if the engineer is already coming to your premises to carry out other work. However, there may be a charge if an engineer is called out for a fault you could potentially fix yourself, for example if there's a fault with the phone equipment in your premises.
So please check your own connections and equipment carefully before arranging a visit by an engineer. See our guide on phone line faults.
For pricing information, go to the BT Price List.