Open Text Corp Customer Service Phone Numbers Customer service: 1-800-499-6544   Open Text Corp Headquarters Info, Email, Phone number, Website and live chat Information OpenText, headquartered in Waterloo, Ontario, Canada is Canada’s largest software company as of 2014 and recognized as one of Canada’s Top 100 Employers 2016 by Mediacorp Canada Inc. If you searching for Open Text Corp Customer Service Number,