Mix up and Slip up

Mix up verb - To fail to differentiate (a thing) from something similar or related.

Slip up and mix up are semantically related In some cases you can use "Slip up" instead a verb "Mix up".

Slip up verb - To make a mistake.

Mix up and slip up are semantically related in make a mistake topic. Sometimes you can use "Mix up" instead a verb "Slip up", if it concerns topics such as miscalculate.