账单 (zhàng dān) literally combines 账 (zhàng), meaning 'account' or 'record of money', and 单 (dān), meaning 'list' or 'sheet'. Together, it refers to an official document listing items purchased or services received, along with their costs — essentially a 'bill' or 'statement'. It’s commonly used in contexts like restaurants, utilities, credit cards, banking, and online shopping.

This word is neutral in register and appears frequently in both spoken and written Chinese. Unlike informal terms like 小票 (xiǎo piào, 'receipt'), 账单 usually implies a more formal, itemized summary — often sent monthly (e.g., phone or electricity bills) or generated after a service (e.g., hotel stay). It may include due dates, payment methods, and account numbers, making it central to personal finance management.