After ordering virtual office service for your existing Estonian company you should change your company's registered office address 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 in the Estonian Business Register.
For changing both registered office address and contact person please see this article.
If you have not yet ordered virtual office service you can do it by following this link to Unicount self-service.