You can do this by entering the details of the joint policyholder when buying the policy online, there will be a question asking if you would like to add any joint policy holders.
Or you can call our customer services team. Before calling please ensure that you have the following details for the additional policyholder: full name date of birth relationship to you occupation and type of business details of any bankruptcies, IVAS CCJS claims history (including liability claims) unspent criminal convictions.