If your plan allows you to make claims for dependents, and your Plan Administrator has given you the access required to add them to your profile, you can navigate to the "Settings" tab of your account to do so. Then, just go to your "Dependents" section and add each person who will be included in your plan coverage. Please note that you will need to enter their birthdates as well.
If you come across an error that says "Please contact your Plan Admin", this means that you will need to reach out to your employer in order to add your dependents.
A dependent that is eligible under an HSA is:
a. ) The employee's spouse by marriage or common-law and/or
b. ) Related to the employee by blood or adoption and living in the same primary residence.
c.) Dependents (not spouses) must be Financially reliant on the employee
There is no age limit on dependents if they fit the above criteria.
Here is a link to the CRA where we reference this information from:
https://www.canada.ca/en/revenue-agency/services/forms-publications/publications/it339r2/archived-meaning-private-health-services-plan-1988-subsequent-taxation-years.html
Check out the below blog if you would like to learn more about dependents!