Finance business in Belgium earned a huge cut, mostly in error (6,2,6)

I believe the answer is:

bureau de change

I'm a little stuck... Click here to teach me more about this clue!

'finance business' is the definition.
I don't know anything about this answer so I can't tell whether this works.

'belgium earned a huge cut mostly in error' is the wordplay.
'belgium' becomes 'b' (international vehicle registration code).
'mostly' means to remove the last letter.
'in error' indicates an anagram.
'earned'+'a'+'huge'+'cut'='earnedahugecut'
'earnedahugecut' with its final letter taken away is 'earnedahugecu'.
'earnedahugecu' with letters rearranged gives 'ureaudechange'.
'b'+'ureaudechange'='BUREAU DE CHANGE'

'in' is the link.

Can you help me to learn more?

(Other definitions for bureau de change that I've seen before include "Where to switch currencies" , "financial dealings here! - with 18a" .)

I've seen this clue in The Telegraph.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.