French phrase
La prochaine fois, merci de ~.
Meaning
Next time, please ___.
When to use it
A polite request for action next time. It often asks for advance notice or preparation.
Example dialogue
La prochaine fois, merci de me prévenir à l'avance.
Next time, please let me know in advance.
Pardon, je te préviendrai la prochaine fois.
Sorry, I'll let you know in advance next time.