What is Threema Broadcast?

Threema Broadcast is a web interface that allows for convenient top-down communications via Threema. Use Threema Broadcast to communicate with employees, customers, and third parties.

Besides classic distribution lists and central groups, where you add and manage the recipients yourself, Threema Broadcast also offers feeds and bots. Feeds are dynamic newsletters; users can subscribe and unsubscribe at any time. Bots allow to conveniently retrieve information via Threema.

What’s the difference between feeds and distribution lists?

Both feeds and distribution lists are meant for top-down communications.

As far as distribution lists are concerned, you decide who the recipients are. You can add and remove Threema IDs to distribution lists at any time.

Feeds are similar to newsletters. Users can subscribe to and unsubscribe from feeds on their own. As Broadcast administrator, you can also subscribe and unsubscribe users from feeds. A feed’s blacklist allows to prevent certain users from subscribing to the feed.

Activate Private Broadcast to prevent external users from subscribing to feeds.

What are centrally managed group chats?

Threema Broadcast allows to centrally create and manage group chats. These chats can be managed directly from the Threema Broadcast interface on a desktop computer. Messages sent to such a group chat will also be sent to the Threema Broadcast server since the respective Broadcast ID is also a group member. However, if the setting “Save chat history” (see below) is disabled, the server will discard incoming group messages right away.

Groups can contain up to 256 members. To send messages to more recipients, please use feeds and distribution lists.

Save chat history

To receive incoming group messages in Threema Broadcast, enable “Save chat history”.

By default, “Save chat history” is disabled. When enabled, the group’s name is prefixed with a cloud icon (“☁️”), which serves as permanent indicator to let group members know whether the group chats’ contents are centrally stored or not. If this setting is changed, all group members will automatically be notified.

Please note that it’s currently not possible to receive media and files, only text messages.

Querying group settings

Members of centrally managed group chats can send “profile” to the relevant Broadcast ID to query the “Save chat history” setting.

Regular groups

Please note: The “Save chat history” setting does not affect groups created in the app. All groups created in the app are managed in decentralized manner, and only group members have access to the chat history, nobody else.

Which message types are supported?

Currently, the sending of text / image and file messages (50MB) is supported. At this time, it is not possible to create polls using Threema Broadcast.

What is a Broadcast ID?

A Broadcast ID is a Threema ID that can be used exclusively in Threema Broadcast. Broadcast IDs begin with an asterisk (*), followed by “BC”, and consist of eight characters in total. You will receive one randomly generated Broadcast ID per price plan. Example: *BC4W4O3

Can I choose a custom Broadcast ID?

A custom Broadcast ID will be created for a one-time fee of CHF 490.–.

Like other Broadcast IDs, custom IDs begin with an asterisk (*) and consist of eight characters in total; the seven characters following the asterisk must be letters or digits, special characters are not allowed. Example: *THREEMA

Threema can reject requested Broadcast IDs without stating any reasons. Custom Broadcast IDs that violate the rights of third parties, in particular trademarks and copyrights, or that violate any law may be blocked by Threema at any time.

Is there an API?

Yes, Threema Broadcast is accessible via a software interface. The API allows to dispatch Broadcast messages and manage feeds, distribution lists, and groups.

For technical details, please refer to the API documentation.

Which browsers are supported?

The most recent versions of Chrome/Chromium, Edge, Firefox, Opera, and Safari are supported.

Internet Explorer ist not supported.

Security and privacy

Which messages are stored in Threema Broadcast?

Outgoing messages

Messages that administrators send with feeds, distribution lists, and in group chats are stored on the Threema Broadcast server and can be accessed by the administrators of the relevant Broadcast ID in the Threema Broadcast web interface.

Incoming messages

Messages that Threema users send to a feed or distribution list are not stored and cannot be accessed by administrators of the Broadcast ID. These messages are immediately deleted from the server.

Only centrally managed groups offer the option to save the entire chat history (including incoming messages).

Duration of storage

Files are permanently deleted after 30 days, and text messages after 180 days in Threema Broadcast.

How are Threema users protected against misuse?

Threema users can block senders from whom they receive unwanted messages.

Broadcast administrators are not allowed to add users to distribution lists or groups against their will. In case of abuse, the relevant Broadcast profile will be revoked.

How is the communication protected in Threema Broadcast?

In Threema Broadcast, all messages are always transmitted in encrypted form. On top of that, incoming messages are not stored (unless the option “Save chat history” is enabled in centrally managed group chats).

Messages sent via the Threema Broadcast web interface are protected using TLS while in transit between your browser and the Threema Broadcast server. The Threema Broadcast server then encrypts the messages again using Threema’s regular end-to-end encryption based on NaCl. The private key of a Broadcast ID is stored in symmetrically encrypted form for each customer to prevent unauthorized access by third parties.

For more information, please refer to the section “Usage Data” of Threema Broadcast’s Privacy Policy.


How is Threema Broadcast billed?

Threema Broadcast’s pricing is straightforward; the number of recipients serves as basis for billing. The number of recipients includes all subscribers to your feeds, all members of your groups, and all recipients of your distribution lists. Users who have subscribed to multiple feeds or are present in multiple groups or distribution lists are counted only once.

The available price plans can be found in the pricing overview.

What’s the minimum subscription term?

The minimum term is one month. You decide in advance for how many months you want to use Threema Broadcast. Once we have received your payment, your Broadcast ID will be activated automatically.

For more information, please refer to the General Terms and Conditions of Use.

Do subscriptions renew automatically?

No, subscriptions don’t renew automatically when the term ends.

Can I send Threema messages from different Broadcast IDs?

Yes. Please note, however, that each Broadcast ID requires a separate price plan (and costs increase accordingly).

Can I increase the number of recipients while a subscription is active?

Yes, you can increase the number of recipients at any time by clicking on “Upgrade now” in the main view of the relevant broadcast ID.

Is there a trial version?

To test Threema Broadcast free of charge and without obligation, activate a Threema Work trial.

Threema Broadcast can be used independently of Threema Work. However, the trial version is only available as part of Threema Work.

Is there a discount for schools and NGOs?

Threema supports nonprofit organizations, schools, and other educational institutions in their endeavor to increase privacy protection with preferential terms on Threema Work.

For Threema Broadcast, no discounts are available.


How do I make sure only intended users can subscribe to feeds and interact with bots?

If the setting “Private Broadcast” is enabled, only internal users can interact with the Broadcast ID in question, i.e., subscribe to feeds and use bots. Internal users are the ones who are present in a distribution list or group.

Private Broadcast is enabled by default and can be changed in “Basic settings”.

If Threema Broadcast is used in conjunction with Threema Work, the distribution list “All” gets populated with all contacts of the corresponding Threema Work subscription.

Private Broadcast: Are external contacts automatically removed from groups and distribution lists when Private Broadcast is enabled?

No, when enabling Private Broadcast, external contacst are labeled, but you have to remove them manually from groups and distribution lists.

Please note that you cannot remove recipients from feeds. If an external contact unsubscribes from a feed after you have enabled Private Broadcast, they cannot re-subscribe to the feed.

Private Broadcast is enabled, but external users can still add my Broadcast ID to their contact list. Why?

No matter if Private Broadcast is enabled or not, any Threema user can add any Broadcast ID to their contact list (provided they are aware of it). However, external users are not able to subscribe to feeds or interact with bots if Private Broadcast is enabled. Thus, a Broadcast ID is useless for external users if Private Broadcast is enabled.

Can I designate multiple administrators for Threema Broadcast?

Yes. You can add as many administrators as necessary, and you can limit their permissions as desired. Navigate to “Access”, and click on “Create new administrator login”.

Is there a list of my Threema Broadcast administrators and their access privileges?

Yes, navigate to Manage > Logins to get an overview of your Threema Broadcast administrators and their access privileges.

Why are members missing from my group chat?

After editing a group (e.g., by adding or removing members), the group needs to be synchronized in order for the changes to become effective in the app.

Open the group in Threema Broadcast, and click the “Synchronize now” button.

System notification of centrally managed group chats: How do I change the language?

Like all automatic system notifications, this notification is in English, and there is no way to switch the language.

Threema Work integration

What is included when using Threema Work?

The Enterprise price plan of Threema Work includes 1 Threema Broadcast ID, where the number of recipients corresponds to the number of Enterprise licenses in Threema Work. If, for example, there are 80 Enterprise licenses in Threema Work, there are 80 recipients available in Threema Broadcast.

The use of multiple Broadcast IDs or the communication with more recipients than Threema Work users is not included and must be purchased by means of a separate Broadcast ID. Additional IDs are not linked with Threema Work.

Why is there a distribution list called “All”?

If Threema Broadcast is used in conjunction with Threema Work, the distribution list “All” gets automatically populated with all contacts of the corresponding Threema Work subscription (synchronization is performed once a day).

This ensures that all internal contacts of your Threema Work subscription are internal contacts in Threema Broadcast (cf. Private Broadcast).

What does the notification “Some of your recipients are not internal contacts” mean?

This notification appears if Private Broadcast is enabled and groups or distribution lists contain Threema IDs that are not internal contacts of your Threema Work subscription. Possible reasons are:
  • A Threema ID that was detached from your Threema Work subscription is still member of a group or recipient of a distribution list.
  • You have added a Threema ID that’s not part of your Threema Work subscription to a group or distribution list.

What happens if I detach users from my subscription in Threema Work?

The users in question will be removed from the distribution list “All” and any other distribution lists. However, they will not be removed from groups and feeds. As administrator, you can manually remove them from groups and feeds.

I can’t log in to Threema Broadcast. Why?

It’s not possible to log in to Threema Broadcast with your Threema Work credentials. Please log in to Threema Work, and use Threema Broadcast via Threema Work’s management cockpit.