AVIS Reservation Number 48522561US3. AVIS wizard Number# UB355V Avis I made a reservation got a rental car at SJC airport. I chose the higher price Avis because they have provided quality service in the past. Because of a change in Covin 19, I had to change my reservation. I dialed the AVIS number of the airport location as provided on the web site. The answer options included either new or modify. I chose modify and was transferred to a call center in Mexico. After a long wait, my call was answered. By then, I was within the 24 hours.