without fail
idiomPart offails
without fail — idiom
1. 1. on every occasion without exception. 2. used to emphasize that something must
1.idiom
Definition
1. on every occasion without exception. 2. used to emphasize that something must be done, especially when giving an instruction or order.
Example
Nellie calls her mother every Sunday without fail, no matter how busy she is.
Please submit your tax forms by April 15th without fail, or you will face a penalty.