Automation and the use of multiple accounts

Keeping Twitter safe and free from spam is a top priority for us. One of the most common spam violations we see is the use of multiple accounts and the Twitter developer platform to attempt to artificially amplify or inflate the prominence of certain Tweets. To be clear: Twitter prohibits any attempt to use automation for the purposes of posting or disseminating spam, and such behavior may result in enforcement action.

In January, we announced that as part of our Information Quality efforts we would be making changes to TweetDeck and the Twitter API to limit the ability of users to perform coordinated actions across multiple accounts. These changes are an important step in ensuring we stay ahead of malicious activity targeting the crucial conversations taking place on Twitter — including elections in the United States and around the world. Today, we’re sharing details about those changes, as well as important guidance for developers on how to comply with these rules.
Please review this guidance carefully, as you may be required to make changes to your application or service.

Do not (and do not allow your users to) simultaneously post identical or substantially similar content to multiple accounts. For example, your service should not permit a user to select several accounts they control from which to publish a given Tweet.

This applies regardless of whether the Tweets are published to Twitter at the same time, or are scheduled/queued for future publication.
As an alternative to posting identical content, you can Retweet content from one account from the other accounts you wish to share that post from. This should only be done from a small number of distinct accounts that you directly control. Please note that bulk, aggressive, or very high-volume automated Retweeting is not permitted under the Automation Rules, and may be subject to enforcement actions.
Do not (and do not allow your users to) simultaneously perform actions such as Likes, Retweets, or follows from multiple accounts. For example, your service should not permit a user to select several accounts they control to follow a specified account.

For additional information on aggressive or inorganic following behavior, please refer to this developer forum post.
For additional information on the appropriate use of automation for replies and mentions, please refer to this developer forum post.
The use of any form of automation (including scheduling) to post identical or substantially similar content, or to perform actions such as Likes or Retweets, across many accounts that have authorized your app (whether or not you created or directly control those accounts) is not permitted. For example, applications that coordinate activity across multiple accounts to simultaneously post Tweets with a specific hashtag (e.g. in an attempt to cause that topic to trend) are prohibited.

While we continue to permit cross-posting outside information (such as weather alerts or RSS feeds) to Twitter using automation, you should only post this content to one account you control.
As a sole exception to this rule, applications that broadcast or share weather, emergency, or other public service announcements of broad community interest (for example, earthquake or tsunami alerts) are permitted to post this content across multiple accounts who have authorized an app.
Today, we’re also introducing changes to TweetDeck’s multiple account functionality to reflect this guidance. Users of TweetDeck will no longer be able to select multiple accounts through which to perform an action such as Tweeting, Retweeting, liking, or following.
If your app or service includes features which allow users to perform simultaneous actions across multiple accounts, you should make changes to bring it into compliance with this policy by March 23, 2018. Failure to comply with these rules could result in enforcement action, up to and including the suspension of associated applications and accounts.
While we provide detailed definitions of what constitutes spam in the Twitter Rules and Automation Rules, you should keep these two policies front of mind whenever you use the Twitter API to publish, share, or engage with content on Twitter:

Posting duplicative or substantially similar content, replies, or mentions over multiple accounts you control, or creating duplicate or substantially similar accounts, with or without the use of automation, is never allowed.
Posting multiple updates (on a single account or across multiple accounts you control) to a trending or popular topic (for instance, through the use of a specific hashtag) with an intent to subvert or manipulate the topic, or to artificially inflate the prominence of a hashtag or topic, is never allowed.
You can ask questions about any of our developer policies, and specifically about this clarification, using the Rules and Policies category in the Developer Forums.