opposite number

WordReference Random House Unabridged Dictionary of American English © 2025

op′posite num′ber, 

1. counterpart;
   equivalent:
   New members with an interest in folk art will find their opposite numbers in the association's directory.

• 1905–10

Collins Concise English Dictionary © HarperCollins Publishers::

opposite number noun

1. a person holding an equivalent and corresponding position on another side or situation