2020年4月1日 · 不客气>别客气>不用谢. In my opinion, 不客气 is used when talking to colleagues, friends, clients...anyone. 别客气 is used when the relationship is a little more close and it's more casual. E.g. (1)Amy and Jack have known each other for 2 years. (2) Amy is a regular of a restaurant. The waiter is familiar with her.