3 sentences

1. 服务员，麻烦买单。

   fú​wù​yuán, má​fan mǎi​dān.

   Waiter, the check, please.

   Source: Dong Chinese Dictionary

2. 上次是我买单。

   shàng cì shì wǒ mǎi​dān.

   I paid last time.

   Source: OpenSubtitles

3. 服务员，买单！

   fú​wù​yuán, mǎi​dān!

   Waiter, the bill, please!

   Source: OpenSubtitles