身份证(shēn fèn zhèng) - identity card in Mandarin

身份证 (shēnfènzhèng) is an "identity card". 身份 (shēnfèn) means "identity, status" and 证 (zhèng) means "certificate, proof", so together the compound is a "proof of identity".

In China, the 身份证 (shēnfènzhèng) is used constantly, for buying train tickets, checking into hotels, and countless other everyday transactions that a British reader might not expect to need ID for, which makes it a genuinely useful word rather than just an exam list entry. This is a different document from 护照 (hùzhào), "passport", which is for travel abroad; a 身份证 (shēnfènzhèng) is the domestic equivalent.

The measure word is 张 (zhāng), the same classifier used for flat objects like 名片 (míngpiàn), "business card": 一张身份证 (yī zhāng shēnfènzhèng).