have somebody's number

have (got) (one's) number

To understand or know someone or something well enough to anticipate what they will do. That team is impossible to beat—they've had our number since 2006! Oh, don't worry, I've got his number—he's a typical brat.
See also: have, number
Farlex Dictionary of Idioms.

have somebody’s ˈnumber

(informal) really understand what type of person somebody is and what they plan to do: Don’t worry, I’ve got his number. I shall be very careful in any business I do with him. You can’t fool me, you know. I’ve got your number.
See also: have, number
Farlex Partner Idioms Dictionary
See also:
  • have (got) (one's) number
  • have someone's number
  • reckon without
  • reckon without (someone or something)
  • words right out of one's mouth, to take
  • outguess (someone or something)
  • reckon on
  • reckon on (someone or something)
  • expect (someone or something) for (something)
  • expect for