Under your belt

If you have an experience or a qualification under your belt, you have completed it successfully, and it may be useful to you in the future.

Some Excerpts:

From TV shows, movies and novels

The Bold and the Beautiful 

John McCook(Eric Forrester) used the phrase “under your belt” while talking to Ashley Jones (Bridget Forrester) in the popular TV show “The Bold and the Beautiful” as shown below: 

Tags: Ashley Jones, Bold & the Beautiful