When Reservation is guaranteed with a Credit card, Deposit, Company / TA voucher etc. An oral or written statement by the supplier (a carrier, hotel, car rental company, etc.) that he or she has received and will honour a reservation. Oral confirmations have virtually no legal worth.
Even written or telegraphed confirmations have specified or implied limitations. For example, a hotel is not obligated to honour a confirmed reservation if the guest arrives after 6 p.m. unless late arrival is specified. Confirmed reservations may be either guaranteed or non-guaranteed.