Maintaining multiple Twitter accounts can quickly become a hassle, even if you use a third-party client designed to easily switch between accounts. If you post the same tweet on both accounts, you risk annoying anyone following both profiles, but that may leave you constantly wondering where to post which tweet. While Twitter does not offer a merge functionality, you can take steps to smooth the consolidation of two accounts into one.
Choosing a Primary Account
Decide which of the two accounts you want to become the primary account. Consider factors such as the current audience of each account: If one has a smaller but more vocal follower base, it may make more sense to make that account the primary one. Choose the account with the larger number of followers if you are not sure.
Twitter allows you to change your account handle at your choosing. This will immediately change the handle your followers see in their timelines, but will retain all existing follower/following relationships, status updates and direct messages. If you'd prefer to combine one account's handle with the other account's follower base and history, you'll need to swap usernames.
If you want to switch handles or create a brand-new handle for your chosen primary account, log in to Twitter and choose "Settings." Type your new handle in the "Username" box.
Switch usernames by temporarily renaming the first account to anything else, so that its username is now free. Log in to the other Twitter account and change the username to the newly free username. Log in to the first account and update its username to the other account's name. For example, if you want to switch @a and @b: rename @a to @c, rename @b to @a and rename @c to @b, in that order.
Backing Up Followers
While Twitter does not offer a follower import or export tool, you can export your entire list of followers to an Excel spreadsheet using the third-party service Export.ly (exportly.com). As of March 2011, you can export up to 10,000 followers for free. Export followers for the account you don't intend to use anymore and manually re-add those friends on the primary account, using the Excel spreadsheet as your list.
Announcing Your Changes
Send a tweet from the account you are no longer using, asking followers to follow the new account instead. Update the Twitter bio to indicate that newcomers should follow the new primary account instead. Depending on the content and volume of former tweets, you may choose to delete all previous updates on this Twitter account to make it clear that it is inactive.
People must use your new handle for replies and direct messages or you will not receive these messages.
Update the new primary account's profile to reflect the new merge, if necessary. For example, you might end the Twitter bio with "Formerly @oldusername" to help alleviate confusion.