Google has quietly added support for moving subdomains, i.e. subdomain.domain.com, to a new domain in the Change of Address tool within Google Webmaster Tools.
If you review the documentation, as of last night, it was updated to include “or subdomain” to the instructions. The new documentation reads:
- Use the Change of address tool when your site move entails a domain or subdomain change, such as changing from http://fish.example-petstore.com to http://example.com or http://example-petstore.com.
- Note: The tool does not currently support the following kinds of site moves: subdomain name changes, protocol changes (from HTTP to HTTPS), or path-only changes.
Previously, you were unable to communicate to Google in Google Webmaster Tools that you are moving a subdomain to a new domain. Now you can, which is a great addition to the change of address tool. Of course, many still want the change of address tool to support HTTP to HTTPS moves, which is currently does not. In either case, setting up 301 redirects is a really good step to also communicate the domain moves.
Menashe Avramov created a screen shot of the document change, which I will embed below as a PDF:
Postscript: On April 14, 2015, Google officially announced this support on Google+. I am not sure why it took them 3 weeks to announce it, maybe they were testing it more.