French phrase
Pourriez-vous me prévenir une fois ~ ?
Meaning
Could you let me know once ___?
When to use it
A polite request to be notified after completion. Common in formal administrative situations.
Example dialogue
Pourriez-vous me prévenir une fois que mon visa sera délivré ?
Could you let me know once my visa has been issued?
Oui, nous vous contacterons dès sa délivrance.
Yes, we will contact you as soon as it is issued.