Reconfirmation (noun)

The act of confirming or establishing something again.

Origin:

Late 19th century: from re- + confirmation.

Examples:

1. The reconfirmation of the reservation was necessary due to a mistake.
2. The reconfirmation of the appointment was done via email.
3. The reconfirmation of the date and time was necessary for planning purposes.
4. The reconfirmation of the details was done over the phone.
5. The reconfirmation of the flight was required for security reasons.