Something that is non-negotiable cannot be changed by discussion.

The terms of this agreement are non-negotiable. 这项协议的条款不容商榷。

A non-negotiable cheque cannot be exchanged for money and must be paid into a bank account.

A non-negotiable financial product cannot be bought and sold.

Time deposits are non-negotiable deposits that are maintained in a bank for a specified period of time. 定期存款必须存入银行一定时间，期间不可兑现。