ActivityPub / Mastodon stick to old account name

I have just began to think about using the ActivityPub-option of, to have the Mastodon-users and their comments on my timeline here. I am long-time user on Mastodon, signing If possible, I would like to keep this instance / account-name in the future.
With I found, that I do have the account in addition. Is there a way, to keep my old account and get it fully connected via ActivityPub? Do I lose my old account name with the migration to
Thanks a lot for some explanations.

I think that the replies in this post will be helpful: Should I see replies to Mastodon posts that were cross-posted?

If you want to see replies in, you’d want to move your followers from your old Mastodon account to your account. But I don’t think that’s what you want.

If you want your content to be sent to Mastodon, you’ll want to use cross-posting.

Mastodon users can reply to your account directly and you would view their comments on your timeline on only if they subscribe to your AcitivityPub account/stream-- which is sort of like moving instances in Mastodon parlance. Your existing Mastodon account is already on the instance, and you cannot use to “take over” managing for that instance.

There’s more details in the other thread, but the short version is you can copy posts from to a Mastodon instance automatically (cross posting) and/or you can treat your account as a subscribe-able account from other services that use ActivityPub and it will interoperate directly (which is kind of like becoming your Mastodon instance, just like you could move from

And just like moving instances within Mastodon, account migration works with some funky caveats.

To add to what @jsonbecker said, one problem is that is a Mastodon instance with thousands of users. In theory, if you were the only user on it, you could migrate it to But because it’s a shared host the best you can do is use Mastodon’s account migration feature to tell everyone about your new ActivityPub username.

To make this easier in the future, I do recommend using a custom domain name for your ActivityPub username on wherever possible. So instead of it could be still powers it behind the scenes but it’s just more flexible later (and gives you a unique username if you want it).

I’m going to try to update the documentation to expand on some of this.

That makes it much clearer, thanks a lot @jsonbecker and @manton. I will stay to this topic and watch out for upcoming details. Thanks a lot for your info!