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In our service area, we provide you with detailed information and downloads on the special technical features of SIMSme and also answer frequently asked questions concerning the app.

If you search for app download links, important manuals and documentations navigate to the page Downloads

FAQ for SIMSme Business

SIMSme Business has been designed to fit the specific needs of corporate users. For example, one feature found only in this version is the ability to configure the app through Mobile Device Management software solutions or the Management Cockpit.

You can read more about SIMSme Business features under “Features”.

Yes, it is possible for SIMSme Business users to communicate with private SIMSme users. Another option is to run both versions of the app on the same device. This ensures a clear separation between private and business communication.

You can switch from SIMSme to SIMSme Business at any time by using the backup process. For more information on how this works, please see the question “Is there a backup function?”

The administrator can use the Management Cockpit to create user accounts and assign licenses. Your employees will then automatically receive an invitation via email or SMS. The SIMSme Business app can be downloaded for free from the App Store. After registration, the user is then automatically added to the groups and channels assigned to him or her by the administrator.

SIMSme Business supports Android for Work (Android 5.0 and newer) and Managed App Configuration (iOS 8.0 and newer), meaning it can be distributed to employees and centrally configured using a Mobile Device Management (MDM) solution. We support the following MDM solutions:

  • MobileIron
  • vmware airwatch
  • IBM MaaS360
  • JAMD software

For more information, please see the related documentation in the Downloads section of this website.

The guaranteed availability level (SLA) for SIMSme Business is 99.5%.

To deactivate specific functions in SIMSme Business, access to the SIMSme Management Cockpit or a Mobile Device Management (MDM) solution is required. Either of those mechanisms allow for configuration of specific security policies, such as minimum password strength. For more information, please see the FAQ on the Management Cockpit and the documentation on the use of MDMs in the Downloads section of this website.

The SIMSme Business app can be downloaded from the App Store and used for 30 days at no cost. After the expiration of that period, users must unlock the app using a login code or in-app purchase.

Please use the order form to request a license. You can also purchase a license right in the app.

Can I purchase additional licenses at some later point if additional users join the company?
Yes, you can expand your existing contingent of licenses at any time. Please use the order form.

Yes, you can expand your existing contingent of licenses at any time via the Management Cockpit. The licenses are then available for immediate activation and can be assigned to user accounts.

General questions about the app

With most problems, it is sufficient to just restart the app.

For this, with iOS, you push the home button of your iPhone twice, subsequently closing the app by swiping upward with your finger.

With Android, please use your device’s task manager. Should the problem continue, please look for the corresponding answer to your problem in our FAQs or contact our support.

With most problems, you just need to restart the app.

For this, with iOS, you push the home button of your iPhone twice, then close the app by swiping upward with your finger.

With Android, please use your device’s task manager. Should the problem continue, please look for the corresponding answer to your problem in our FAQs or contact our support.

To connect you with your colleagues via SIMSme Business, we need some kind of identification. Identification takes place via the phone number. During the registration process, you receive an SMS that makes sure that you have access to the given phone number.

You have the possibility to store your chat history and your contacts in a back-up. Your back-up will be encrypted and deposited in iCloud or Google Drive protected by a password and in a new installation can be used to retrieve your old data. In this way, you can change devices without losing data. To install a back-up, please open the settings of the app and tap “Backup”. You initially need to create one first back-up and can subsequently determine the intervals at which automatic back-ups are to be made.

To restore data from the back-up, please follow the normal registration process after the new installation. If your phone number is recognized, you will automatically be informed about your possibilities of reinstalling a back-up.

Please make sure that you have stored the mobile number of the corresponding colleagues in the telephone book of your smartphone. Alternatively, you can use the email directory. This feature automatically indicates all users that have registered with the same corporate email domain as you without the need of having them saved in your phonebook, making it easy to find fellow co-workers.

All messages sent via SIMSme are encrypted symmetrically according to AES-256 on the smartphone of the sender and SSL-encrypted via SIMSme server and conveyed to the receiver. In order for the receiver to be able to read the message, he needs the corresponding key.

This key is asymmetrically encrypted for each receiver of the message individually via RSA-2048-technique and sent. In doing so, a public key is used to encrypt and a private key is used to decipher, whereby the private key never leaves the smartphone of the owner and is only stored locally. The key that is finally needed to read the message can thus only be deciphered on the phone of the corresponding receiver. Other communication partners, such as ourselves, as SIMSme operators, or possible attackers that get hold of the AES key are thus unable to read the encrypted message.

You can obtain further information on this subject at

Documents, media, contacts and locations: On the left side of the chat windows, next to the text input field, there is a “+” symbol. Tap this and choose the desired type of document and document from the context menu.

Voice messages: As long as no text has been typed in, you see a microphone symbol on the right side of the text input field . Tap this and hold it pressed to record a voice message.

A self-destructing message erases itself automatically after a certain amount of time on the receiver’s smartphone. You can set up a countdown so that the message is erased after a predefined amount of time or choose one specific time when this message should cease to be available anymore. For this, tap “self-destruction” under the text input field and choose the required setting.

With a timed message, you can determine when it is sent. For this, tap under the text input field on “Timed message” and choose the desired time. Messages that have been timed, but have not been sent yet are shown in the corresponding chat in a list view. You can find these by tapping the clock symbol in the upper right of the chat window.

The color code of your SIMSme contacts tells you how sure you can be about the identity of a specific contact.

Red status: We found the contact, which means your contact also uses SIMSme, however you have not chatted yet with each other.

Yellow status: You have already communicated with the corresponding contact. You or your contact have already sent a message to the other and your counterpart has confirmed the contact.

Green status: The highest level of trust, for which you and your contact not only must have been in contact with each other once before, but also must have personally met and must have exchanged your SIMSme key by scanning the QR code. The QR code is called up via “Settings => Profile”. You can do a scan by opening the corresponding contact under “Contacts” and then tapping “Scan contact”

General questions about the web messenger

If you decide to trust the browser you are using, your data will be encrypted and saved locally. This allows you to access this information easily at a later date. If you do not trust the browser, if, for example, you are using SIMSme in an unsecure environment, a temporary session is created and the data will not be permanently saved on the browser being used. In order to protect your data, all content from the browser session will be deleted after you sign out.

Your profile picture, name or status can be changed in just a few short steps. Tap “Profile” in the menu. Here, you can choose a new profile picture, change your profile name and set your own status. Under “Profile” you can also amend and verify the mobile number and e-mail address linked to your account. If your profile is managed by an Administrator, it may not be possible to change some data fields such as Name or Department. Your SIMSme ID cannot be changed either. This ID remains the same for as long as you use SIMSme – and allows other users to find you.

Please check your system settings. Go to “Settings” and check whether notifications are allowed in general and whether audio notifications are turned on.

There are various different ways of finding and writing to contacts. If you already use SIMSme on your smartphone, the address book will be transferred automatically via the device coupling feature. These contacts will then be displayed under “My contacts”. If you have verified a company e-mail address, you will be able to find other colleagues with the same e-mail domain in the directory. If your account is managed by an Administrator, you will now also be able to look through the directory for your colleagues using their name or e-mail address. What’s more, you can also look through the directory using the complete mobile numbers and e-mail addresses of other users in order to contact them.

Following Release 2.1, it is now possible to use several devices including smartphones or desktop browsers via the same account. The content of your communications will be synced via your devices. To add a new device to your account simply use one that is already linked to your account and go to “Settings”, tap “Manage device” and then “Add device”. A 9-digit authorization code will be displayed. You then have 5 minutes to enter this code into the registration screen on the new device. Then check the data relevant to the new device (name and key number) on the existing one and authorize the new device. Once the devices have been successfully coupled, messages and contacts will be synced between the devices.

The device password is an important security anchor when it comes to protecting your data. It should be made as complex as possible and will be requested whenever the application is launched. For reasons of security device passwords are not saved on SIMSme servers. In the event that you forget your device password you can request a Recovery Code to unlock the application. To do so, click on “Password forgotten” in the registration screen and select the channel (SMS or e-mail) via which you would like to receive the code. In the background, your local application will send a Password Recovery Token to the server to generate your Recovery Code. As soon as you have unlocked the application with the Recovery Code you will be able to set a new device password for your application. Please note: Managed accounts require the authorization of the Administrator before a Recovery Code can be sent.

Tap on the Paperclip icon to the left of the text input field to send images, videos, files and contacts. Select the attachment you wish to send from its current location and a preview screen will open. Here you can add further attachments should you wish to send more than one attachment at once. Any message you also wish to compose in the input field will be displayed below the final attachment.
The microphone symbol to the right of the text input field lets you record and send voice messages. The first time you want to record a voice message, the browser will ask permission to access the microphone.

Next to the text input field are three vertical dots. Here, each message can be allocated high priority, a sent time or a self-destruct request – any combination of the 3 options is possible.
High priority: High priority messages are highlighted to emphasize their urgency. The push notifications and preview banners for such messages are also marked as “Important”.
Time sent feature: The time sent feature lets you set the time at which the message is to be sent. Tap “Time sent” under the text input field and select a time. Messages attributed with a time to be sent that has not yet been reached are displayed in the respective chat with a clock symbol. The message is then sent automatically at the designated time.
Self-destruct feature: Self-destructing messages are deleted automatically from the recipient’s device after a given length of time. You can set up a countdown so that the message deletes itself after the set amount of time or select a specific time after which the message is no longer available.

You can see how sure you can be of your contact’s identity based on the color coding of your SIMSme contacts.
A red status means that we have found the contact — that this contact is using SIMSme, but that you have not yet chatted with each other at this point.
Yellow means that you have been in contact before. You and your contact have already exchanged messages at an earlier point in time and the other person has confirmed that he knows you (his contact).
Green is the highest level of trust. In order to achieve green status, you not only have to have exchanged messages before, but you also have to have met in person and exchanged your SIMSme keys by scanning the associated QR code.

All message sent via SIMSme are symmetrically encrypted on the sender’s phone using AES-256 and transmitted to the recipient via the SIMSme servers using SSL encryption. Your recipient needs the proper key in order to read the messages. This key is asymmetrically encrypted and sent individually to each recipient of the message using the RSA-2048 method. With this approach, a public key is used for encryption and a private key for decryption. The key, which will ultimately be needed to read the message, can only be decrypted on the respective recipient’s device. Other communication partners, Deutsche Post in its capacity as operator of SIMSme, as well as any other would-be attackers who might be attempting to acquire the AES key, are therefore incapable of decrypting and reading the encrypted message. For more information, please head over to:

FAQ to the Management Cockpit

A designated administrator can test the Management Cockpit, even before a concrete number of licenses has been ordered. To do so, simply register your company and a designated administrator. Confirmation and access data to the Management Cockpit will then be sent to you. You can decide thereafter how many licenses you wish to order.

For security reasons, the Management Cockpit is secured through a personal browser certificate. After registration the denoted administrator will receive the certificate via email. Once this is installed, the Management Cockpit can then be loaded.

First double-click on the certificate. On a Windows computer this will launch the “Certificate Import Wizard,” while on a Mac it will open the “Keychain.” Follow the instructions to import the browser certificate and enter the 6-digit certificate code from the text message you will have received. The certificate will now be stored centrally and available to the computer’s various browsers. We recommend using the latest version of Internet Explorer, Chrome, Firefox or Safari. Use one of these browsers to open the link to the Management Cockpit contained in the email.

We review each new registration individually, which can sometimes take a bit of time. We apologize for the inconvenience. If you haven’t received your login data within one working day, please contact us directly at

A certificate is a digitally signed procedure that allows for secure transmission of information on the internet. Certificates are commonly used by web browsers, email and chat apps. When you exchange information with secure websites such as the SIMSme Management Cockpit, that data is sent in encrypted form. This protects your login and other information.

The following links contain more information about how to import and manage certificates on your operating system.

on Windows 7:
Microsoft provides general information about certificates and their components under Windows 7 here. We’ve included a section earlier in this FAQ on how to import a certificate using the “Certificate Import Wizard.” For more information on the import process, please click here.

on Mac OS:
Apple provides general information about certificates and how they work under macOS Sierra here. We’ve included a section earlier in this FAQ on how to import a certificate using the “Keychain.” For more information on the import process, please click here.

Once you’ve installed the certificate, please terminate the browser software completely and then load a fresh copy of the Cockpit. The Management Cockpit looks for the browser certificate the first time it is opened. Depending on which browser you’re using, a dialog box will open asking you to confirm the stored certificate.

Some browsers such as Firefox cannot automatically access your computer’s central certificate library. In the browser settings section, navigate to Certificates (in Firefox > Settings > Data Privacy & Security > Certificates > View Certificates > Your Certificates) and import the certificate from wherever you have stored it. To make this process easier, store the certificate in an easy-to-find location such as the Desktop. Close the browser and then reopen it. You can now open the Management Cockpit.

The Management Cockpit uses JavaScript. Your browser may have Javascript deactivated by default. These settings can change when you update your browser or install new security software or security patches. If you experience problems with the depiction of the Management Cockpit, please check whether JavaScript is activated. The following links provide information on how to activate Javascript: Google Chrome, Mozilla Firefox, Microsoft Internet Explorer or Apple Safari.

Your browser’s handling of certificates can vary by browser type and your company’s specific IT security policies. You will always be asked to confirm the certificate the first time you start the Cockpit. This is necessary to authenticate yourself as a verified user. The browsers can be configured to remember that setting:

on Internet Explorer and Chrome:
If IE or Chrome (on a Windows PC) continues to request confirmation of the certificate beyond the first time you call up the Cockpit, please open “Display Certificate Properties” and then choose “Install Certificate” via the “Certificate Import Wizard.” If you selected the destination folder as a “Trusted Publisher” in the “Certificate Library” and then confirm the change, the browser will then recognize the certificate as trustworthy and will stop requiring confirmation.

on Firefox:
The Firefox browser has the listed functionality to remember this setting and automatically verify the certificate upon launch instead of requiring confirmation. Unfortunately some Firefox versions contain an unresolved bug that prevents this from working properly.

After registering and logging in to the Management Cockpit for the first time, you are sent an email with your personal Recovery Password. Use it to reset your password by clicking the “Password Forgotten” link on the login screen of the Management Cockpit. Please note that the Recovery Password can only be used one time. If it is used to log in, you will automatically be sent a new Recovery Password via email.

Yes, absolutely. You control who can access SIMSme Business through license assignment. Create a user account and assign a license for those users you wish to add. You can review when licenses expire on the License Overview page.

No, it is possible to create user accounts based solely on a mobile number. If, however, a business email address is provided, the user will receive the invitation by email, not text message, and can access the shared email directory within the app.

SIMSme Business makes it possible to set up as many internal company channels as desired. You can specify the recipients for each channel individually, including assigning write permissions for the channel.

“App Settings” allows for custom management of individual functions — from media and password guidelines to password complexity — to allow you to satisfy your compliance guidelines. Any changes you apply will become active within 24 hours.

SIMSme Business can be customized to fit your company’s specifications, including a corporate logo and a color scheme to match your corporate design. The “App Design” section allows you to upload a logo and change the color scheme. The preview function lets you review the current design of the app at any time. Once you apply the changes, they will be visible to users within 24 hours.