ðɪs tˈɪkɪɾɪŋ pˈɑːlɪsi wʌz nˌɑːt ɛkstˈɛndᵻd tə ðə fˈɔːɹmɚɹ ˌoʊvɚɡɹˈaʊnd nˈɛtwɜːk, ænd fɚɹə nˈʌmbɚɹ ʌv jˈɪɹz ˈɔɪstɚ kˈɑːɹd pˈeɪæzjuːɡˌoʊ tˈɪkɪts wɜː nˌɑːt vˈælɪd æt stˈeɪʃənz bˈɛɹɪŋ ðə "ˈɔn" bɹˈænd, dᵻspˈaɪt ðə sˌɪmɪlˈæɹᵻɾi ʌvðə tˈuː nˈɛtwɜːk bɹˈænd nˈeɪmz.
This ticketing policy was not extended to the former Overground Network, and for a number of years Oyster card pay-as-you-go tickets were not valid at stations bearing the "ON" brand, despite the similarity of the two network brand names.