bank on

bank on

To rely on a future occurrence (even though it might not happen). I've really been banking on a holiday bonus this year—I don't have enough money to buy presents without it. I don't think you can bank on Tom coming tonight—he's really unreliable.
See also: bank, on
Farlex Dictionary of Idioms.

bank on something

Fig. to be so sure of something that one can trust it as one might trust a bank with one's money. I will be there on time. You can bank on it. I need a promise of your help. I hope I can bank on it.
See also: bank, on
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

bank on

Rely on, count on. For example, You can bank on Molly's caterer to do a good job. This expression alludes to bank as a reliable storage place for money. [Late 1800s]
See also: bank, on
The American Heritage® Dictionary of Idioms by Christine Ammer.

bank on

v.
To rely on someone or something: You can bank on her to get the job done when it has to be done quickly. I wouldn't bank on the bus arriving on time.
See also: bank, on
The American Heritage® Dictionary of Phrasal Verbs.
See also:
  • banking
  • all in (one's) head
  • a thing you don't want is dear at any price
  • (I) won't tell a soul
  • cast (one's) lot in with (someone or something)
  • cast lot in
  • don't count your chickens
  • don't get me wrong
  • don't beat a dead horse