Phrases Phrases for Making Reservations

I want to cancel my reservation.

Meaning

I want to void my booking.

John: Hello, I'd like to speak to someone about a reservation.
Alice: Certainly, sir. How can I help you?
John: I need to cancel my booking for tonight. <b>I want to cancel my reservation</b>.
Alice: May I have your name and reservation number please? Okay, I've cancelled it for you. Thank you. I've confirmed that <b>I want to cancel my reservation</b>.