There are, however, some exceptions: in some countries (like Egypt), calls are charged at the same rate regardless of area and in others (like the UK) an area code is occasionally treated as two areas with different rates.
С 20 мая 2005 года звонки между зонами Мумбаи и Махараштра, Шеннаи и Тамилнаду, Калькутта и Западная Бенгалия и Уттар Прадеш (западный) и Уттар Прадеш (восточный) объединены в Inter service area connectivity.