Working at a monitor is paying off (12)

I believe the answer is:

amortisation

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

'working at a monitor is paying off' is the definition.
I can't judge whether this defines the answer.

'working at a monitor is' is the wordplay.
'working' is an anagram indicator.
'at'+'a'+'monitor'+'is'='atamonitoris'
'atamonitoris' with letters rearranged gives 'AMORTISATION'.

Can you help me to learn more?

(Other definitions for amortisation that I've seen before include "Writing off value" , "reduction in value over the years" .)

I've seen this clue in The Times.

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.