French phrase
Non, je n'ai rien à déclarer.
Meaning
No, I have nothing to declare.
When to use it
It says that the speaker has no items to declare. Common as a polite response to a customs question.
Example dialogue
Avez-vous quelque chose à déclarer ?
Do you have anything to declare?
Non, je n'ai rien à déclarer.
No, I have nothing to declare.