Liberty Life refuses to update my beneficiary

I tried to update my beneficiary, however Liberty Life refuses to update my beneficiary, because I do not have the persons ID number. I have the full names and date of birth as well as contact details. I do not want the person that I nominate to know that they are a beneficiary as I do not want to create expectations. If I ask the person for their ID number, they would want to know why I want it. People are not comfortable giving their ID numbers as there is always a possibility of ***** being committed. I have updated my beneficiaries before, without the ID numbers, just the date of birth.