What it means
The bill, please. Literally "buy the list." 结账 (jiézhàng) is the other common word.
When to use it
In China, arguing over who pays is a genuine social ritual. Saying 我来买单 (I'll get it) is a friendly move — expect resistance.
What Chinese people actually say
Say this instead: 结账 (jiézhàng)
Both are correct, but 买单 is southern (from Cantonese) and 结账 is more common in the north. Either one works anywhere — nobody will misunderstand you. Just don't be surprised if a northern waiter hears 买单 and pauses for half a second.
Examples
fú服wù务yuán员，mǎi买dān单！
Waiter, the bill please!
jīn今tiān天wǒ我lái来mǎi买dān单。
I'll get the bill today.
wǒ我men们fēn分kāi开mǎi买dān单。
We'll pay separately.
The full set of survival phrases for greetings, dining, shopping, and getting around, each with audio.