slip up

US /ˈslɪp ʌp/
UK /ˈslɪp ʌp/
"slip up" picture
1.

make a careless error

:
I hope I don't slip up during the presentation.
The company slipped up by not checking the data carefully.
1.

a careless mistake or error

:
It was just a minor slip-up, nothing serious.
One slip-up could cost us the entire project.