电话上的井号键英文怎么讲?

找个公用电话机,随便拨个接入码,比如：201,
然后就听到普通话按1,英语按2,这时候按2,然后它就会说：请输入卡号,按井号结束.and end with the hash key.这时候就能听到井号的英语是个啥：）,就是这个hash key .
井号的其他说法还有：
In North America,"pound key"
In some countries with British tradition,"hash key"
"number sign" is also used by some