After ordering virtual office with contact person service for your existing Estonian company you should change your company's registered office address and contact person online via Estonian Business Register or notary. It is possible if you are a board member of the company and have unlimited representation rights.
Here is a step-by-step guide for changing your Estonian company registered office address and contact person in the Estonian Business Register.
If you are a resident board member and do not need a contact person service there is another manual available here.
If you have not yet ordered virtual office with contact person service you can do it by following this link to Unicount self-service.