ðə tɹænsˈɪʃən tʊ ˈɔːlfˈɪɡjɚ dˈaɪəlɪŋ ɐlˈaʊd ðə kˈoʊdz təbi ɡɹˈuːpt ˌɪntʊ ˈeɪt sˈɛktɚz; ˈɔːl ɛkstʃˈeɪndʒᵻz wɪðˌɪn ʌvðə sˈɛntɚɹ ʌv lˈʌndən fˈɔːɹmd ðə sˈɛntɹəl sˈɛktɚ ænd ðɪ ˈʌðɚ sˈɛktɚz ɹˈeɪdɪˌeɪɾᵻd fɹʌm ɪt.
The transition to all-figure dialling allowed the codes to be grouped into eight sectors; all exchanges within  of the centre of London formed the Central sector and the other sectors radiated from it.