yùliú shǒujīhào shì yínháng xìtǒng lǐ bǎngdìng de ānquán shǒujīhào bù zhǐshì pǔtōng liánxì fāngshì

预留手机号是银行系统里绑定的安全手机号，不只是普通联系方式。

The registered phone number is the secure phone number linked to the bank system, not just a regular contact number.