有關英國巴士問題

halo, 我係英國讀書既, 希望幫到你丫 =]
1) 英國既巴士係冇自動售票機, 同上面果個人答既一樣, 好多都係要上到車先可以買, 但係呢, 如果你係買一d長途既巴士, 好似出機場, 或者係一d去好遠地方既巴士既話, 咁你就要去巴士站附近既ticket office買既, 但係大部既情況都係會係巴士司機賣既 =]
2) 係丫, 有錯既, 係london先可以用oyster黎"bi"個巴士, 但係如果係去英國旅行既話, 就唔suggest買, 因為只係用得一陣, 同埋其他地方都冇得用的...(記住只係london入面既巴士先可以用架 =]
3) 如果你係上到巴士先買ticket, 咁佢就會俾你既, 唔會收番, 如果你係買一d day return既ticket, 就咁俾佢地 (司機) 睇就ok架啦, 佢地係唔會收番既, 但如果你只係買左一程, 咁你山3要再買過架啦 =]
4) 只係得一個方法, 就係俾cash 既, 佢地係唔會收卡架!!
** 提提你, 有d火車ticket買既時候係包埋任搭巴士架, 你只要show張火車ticket俾佢地睇, 佢地就會知道架啦, 佢地唔會收番, 仲可以再用tim =]
有d咩問題再email我丫, 希望幫到你 =]

If you mean London Bus, then there are ticket machine at most bus stops:
http://commons.wikimedia.org/wiki/Image:London_bus_ticket_machine.JPG

If you mean bus outside London, then most likely you have to buy ticket on board

If you mean National Coach, then you can buy online / ticket office