短信验证码

Almost every Chinese app authenticates via SMS code on a Mainland-issued phone number tied to your real-name ID - passwords are often optional. This makes registering for Chinese apps difficult for foreign users without a +86 number. The standard checkout/login flow: enter phone, 'send 验证码', enter 6-digit code from 短信.

Often shortened to just 验证码 (yànzhèngmǎ, 'verification code') in spoken contexts. The full term is most common in written instructions and form labels. 短信 = SMS / text message.