Banana Accounting for Microsoft Teams

Banana Accounting is now available in Microsoft Teams. With the new Banana Teams App, you can manage your accounting directly from the Teams window, open files stored on OneDrive or SharePoint without downloading them, and share them with your team without switching tools.

With Banana Teams App, it feels like working in the cloud. On any device where Teams is installed, you can open and save files with Banana without any additional login. Unlike other cloud-based accounting software, however, you remain in full control of your data and can copy and move your files. 

The app appears as a personal tab in Teams. Once installed, you can find it in the Teams sidebar or within one of your team's channels, just like any other Microsoft or third-party app.

Features

In short, the app allows you to:

• Manage your accounting within the Teams workspace, alongside chats, meetings and documents
• Open and edit .ac2 files stored on your device, OneDrive or SharePoint
• Save changes directly to the cloud, keeping files available to your colleagues
• See whether other users currently have the same file open
• Open a file from a shared link (1drv.ms, onedrive.com, sharepoint.com) or a public URL
• Quickly find recent and favourite files, synchronised across devices

The app is suitable for both individual use and teamwork in accounting firms, associations, NGOs and small and medium-sized businesses.

Limitations

Teams is based on browser technology and therefore still has some limitations. 
Banana Teams App is still under development and may not offer all the features available in Banana Desktop.

• Teams does not allow different zoom levels for individual tabs or separate windows.
• Attachments cannot be accessed for files stored in the cloud. 
• Switching from the Banana tab to another tab and back may take some time to load. 
  Teams may also close the tab. It is better to open Banana in a new window.

Installing Banana Teams App 

Prerequisites 

To use Banana Teams App, you need:

• A business or school Microsoft 365 account (a personal Microsoft account, such as Outlook.com, is not sufficient because the app uses Microsoft Teams single sign-on authentication)
• The Microsoft Teams application (desktop, web or mobile version)
• Storage space on OneDrive or SharePoint for your accounting files (recommended but not required, as you can also open and save files from your device)
• Permission to install apps from the Microsoft Teams Store. In some organisations, the IT administrator must first allow the app or approve its permissions.
• A modern browser if you use Teams in a browser: an up-to-date version of Edge or Chrome. WebAssembly is also supported by recent versions of Firefox and Safari.
• The app is NOT available for personal accounts because they do not support single sign-on.

You do not need to install any additional software on your computer: the entire Banana Accounting application is loaded within Teams.

Enabling the app for your tenant

Banana Accounting is available from the Microsoft Teams Store. If your Microsoft 365 tenant allows apps published in the Store to be installed, you can search for it directly in Teams and add it like any other app.

However, actual availability depends on your organisation's settings. The Microsoft 365 administrator can:

• Allow the installation of apps published in the Teams Store
• Block or approve individual apps
• Make the app available only to specific users or groups
• Automatically install or pin the app for users
• Require administrator consent for the app's Microsoft 365 permissions

How to add Banana Accounting Teams App

To add it to your Teams:

1. Open Microsoft Teams
2. Click the Store icon (+) in the left sidebar
3. Search for Banana Accounting
4. Click Add 
5. Confirm the installation

If you cannot find the app, contact your organisation's IT administrator and ask them to allow Banana Accounting in Microsoft Teams.

Technical notes on installation

Banana for Teams is an application published on the Marketplace and is automatically updated whenever we release a new version. 

• When you install the Teams App, it runs within the workspace and computing environment provided by Microsoft.
• Microsoft Graph serverless Azure Functions (OneDrive/SharePoint) are used to open and save files. These services are managed by Microsoft and, according to Microsoft's specifications, process requests in a serverless environment without retaining copies of the data. 
• Banana.ch, as the software developer, has no access to your storage spaces. It does not receive copies of your data, cannot see what you do, and cannot access or modify your files. 

Launching Banana Accounting for Teams

To launch the app, go to the sidebar and click ... (View more apps), then select Banana Accounting from the list.

Tip:
You can pin the app to the sidebar by right-clicking it and selecting Pin. This allows you to open it with a single click.

First launch and sign-in

The first time you open Banana Teams App, you will see a loading screen with the message "Loading Banana Accounting...". The app is downloading the Banana engine and preparing the workspace. This may take a few seconds or longer, especially on the first launch or with a slow connection.

When launching the app for the first time, you may be asked to consent to Microsoft 365 permissions.

• In some tenants, users can grant consent directly.
• In other cases, administrator approval is required.
• These permissions are needed to identify you and to open and save, on your behalf, the .ac2 files you have access to on OneDrive and SharePoint.

Once loaded, the Banana Accounting interface is identical to the one you already know from the desktop version.

Open in a new window

When you launch Banana directly in the Teams window as a new tab, that window is automatically closed when you switch to another Teams tab.

It is therefore better to open the app in a new window:

• In the sidebar, right-click Banana Accounting Teams App and select Open in new window.
• Alternatively, while using Banana Accounting Teams App, click the ... menu in the top-right corner and select Open app in new window.

File access (single sign-on)

Once you have signed in to Teams (single sign-on), Banana automatically gives you access to all your files and shared resources.
If this is your very first time, Teams or Microsoft 365 may ask you or your administrator to grant the app access permissions for:

• Your user profile
• Your OneDrive files
• The SharePoint sites you have access to
• The basic information needed to display collaborator presence

These permissions allow the app to open and save files and show who else has the same document open. Without the required permissions, the app's cloud features cannot work.

Opening and sharing an accounting file

To open a file, click Open in the Banana menu or use the recent files start page. The Load file from device or cloud window opens, divided into four tabs:

Local device 

• The Device tab allows you to select a .ac2 file saved locally on your computer. 
• Click Open from device, select the file using the system file picker, and Banana will load it immediately.
• Files opened from your device are not added to the recent files list because they do not have a permanent cloud identity.

OneDrive

• The OneDrive tab provides a file browser for your personal files on OneDrive for Business. 
• Browse folders and subfolders just as you would in OneDrive in your browser. The available columns show the name, size, modification date and person who made the modification.
• Click a .ac2 file to open it: the app securely downloads its contents without requiring you to leave Teams.

SharePoint

• The SharePoint tab lists the SharePoint sites you have access to. 
• Select the desired site, then browse its document libraries to find the file. 
• The structure is identical to OneDrive: folders, files and navigation breadcrumbs.
• If you belong to many sites, you can return to the root by clicking the home button in the breadcrumb navigation.

Open from URL (shared files)

• The Paste URL tab allows you to open a file using a link. This is useful in three situations:
  1. A colleague has shared a link to a file on OneDrive or SharePoint (1drv.ms, onedrive.com, sharepoint.com): paste it here and the app will open it using the Microsoft Graph sharing system
  2. You have a direct link to a public .ac2 file on a web server (HTTPS or HTTP)
  3. You are opening a link generated by another Banana application

Microsoft shared links

When a colleague shares a .ac2 file with you from OneDrive or SharePoint using the Microsoft 365 Share feature, you receive a URL such as https://...sharepoint.com/....+You can:

• Paste it into the app's Paste URL tab
• Open the file from OneDrive or SharePoint using the Open with Banana Accounting option, when available in the file menu

The app automatically recognises Microsoft domains (onedrive.com, 1drv.ms, sharepoint.com) and uses the Graph sharing system to download the file with your permissions.

Paste the link into the File URL field and click Open URL. Only http://+and https://+links are accepted.

Tip: the Ctrl+V shortcut (or Cmd+V on Mac) also works inside the Teams window, even though Teams generally restricts clipboard access for security reasons.

Reload button

When browsing OneDrive or SharePoint, you will find a button with a reload icon in the top-right corner of the window. Click it to refresh the list of files and folders, for example if a colleague has just uploaded a new document.

Open with Banana Accounting

When Microsoft 365 file integration is available in your tenant, .ac2 files stored on OneDrive or SharePoint may display the Open with Banana Accounting action. Selecting it opens Banana Accounting directly in Teams and loads the selected file.

This feature depends on the app being published in the Teams Store, the availability of integration in your tenant, and the policies configured by your administrator.

Opening files from shared links

Banana Teams App supports deep links, which open a specific file directly instead of displaying the app's start page.

There are two ways to use them:

1. Teams deep links
   If you use a Teams link that points directly to a file (with the fileId and source parameters), the app automatically opens it on launch. This is useful, for example, when adding a link to an accounting file in a Teams message or a channel tab: anyone who clicks it is taken directly to the open file.
    
2. Recent and favourite files
   The Banana start screen shows your recently opened files (up to 8) and those you have marked as favourites.

Synchronisation across devices

Recent and favourite files are stored both locally and in your cloud profile, so you can find them even when opening Teams from another computer. Synchronisation is automatic.

The list contains file references, such as the name, location and cloud identifier. It does not contain the contents of the .ac2 files.

Available actions

• Open: click a file to reopen it. The app downloads the latest version from the cloud, not an outdated copy.
• Open file location: takes you directly to the folder containing the file in the OneDrive or SharePoint file browser.
• Add to favourites: marks a file as a favourite. Favourites are never automatically removed from the list, even when you open new files.
• Remove from recent: removes an individual entry from the list (the file remains in the cloud).
• Clear all: completely clears the recent files list.

Files opened only from your device are not stored in the recent files list because they do not have a unique cloud reference.

Saving the file

Banana automatically distinguishes between two situations:

• Save (Ctrl+S): if the file comes from the cloud, it is updated directly in its original location (OneDrive or SharePoint), without prompting you
• Save As: opens the save window, where you can choose the location, file name and destination

When the file comes from your device, even a simple Save opens the save window. This is necessary because, for security reasons, browsers cannot automatically overwrite local files.

The save window

The save window offers three destinations, similar to those available when opening files:

• Device: downloads the file to your computer (the browser's Downloads folder)
• OneDrive: saves the file to your personal OneDrive, allowing you to choose the destination folder
• SharePoint: first select the site, then the folder

The File name field allows you to rename the file before saving.

Smart upload

For large files, the app automatically divides the upload into several parts, making the saving process more resilient to network interruptions. Smaller files (under 4 MB) are uploaded in a single step. You do not need to do anything: the app chooses the best method automatically.

During saving, you will see a series of status messages:

• "Exporting .ac2 from Banana..."
• "Checking remote version..."
• "Preparing upload payload..."
• "Uploading to OneDrive..." (or SharePoint)
• "File saved to OneDrive."

Version and conflict management

When working on a shared file, a colleague may modify and save it while you still have it open. Banana Teams App automatically detects this situation by comparing the remote file version with the version currently in your memory.

If the remote version has changed when you try to save, the app does not automatically overwrite your colleague's work. Instead, it displays a Remote file has changed dialog with three options:

• Overwrite: forces your version to be saved, discarding the changes made by your colleague. Use this only if you are sure of what you are doing.
• Save As: saves your work as a separate copy. The app automatically suggests a name such as FileName (conflict 2026-05-09 10-30-15).ac2, so you can compare the two versions later.
• Cancel: closes the dialog without saving, allowing you to reconsider what to do.

The app also checks the opposite scenario: if the remote file has been deleted while you were working, you are prompted directly to save your conflict copy.

Collaborator presence

When you open a .ac2 file from OneDrive or SharePoint, Banana Teams App tells you whether other colleagues in your organisation currently have the same file open. Their avatars (Microsoft 365 profile pictures) appear next to the file name.

This helps you to:

• Coordinate with colleagues before making important changes
• Avoid version conflicts, for example by agreeing on who should save first
• Immediately see who is viewing or editing the same file

Presence information is updated approximately every 30 seconds and automatically stops when you close the file or the app.

Technical note: presence does not share file contents or real-time changes. It only shows who is working on the same file. Actual changes still follow the "open - edit - save" process, just like in the desktop version.

Languages and theme

Supported languages

The Banana Teams App interface is available in:

• Italian
• English
• German
• French

The language is selected automatically based on your Teams language settings. If Teams is set to Italian, the app will also be in Italian. If your language is not supported, the app uses English as a fallback.

Light and dark theme

The app follows the Teams theme: light, dark or high contrast. When you change the theme in Teams, the app automatically adapts to the new colour scheme.

Privacy and security

The security of your accounting data is a priority. Here is how the app's architecture is designed:

• Single sign-on: you do not need to enter your password again. The app uses the Teams authentication token through the On-Behalf-Of flow, Microsoft's standard for Teams apps.
• Tokens are never exposed to the browser: access tokens for OneDrive and SharePoint are never stored in the browser or local storage. They are handled exclusively on the server side.
• Microsoft Graph behind the scenes: communication with OneDrive and SharePoint always goes through a dedicated backend service, which acts as a secure intermediary between the app and Microsoft Graph. Your browser never calls the Microsoft Graph APIs directly.
• File integrity during transmission: .ac2 files are transmitted byte for byte, without transformations that could alter their contents. The app may keep temporary technical or recovery copies only on the user's device, in IndexedDB, the browser's local database, to protect unsaved work. These copies are not used to share your data with other services.
• Permissions limited to the app's purpose: the app requests the permissions needed to identify you, read and write files you have access to, and display collaborator presence. It does not request access to emails, calendars or chats.

You can find more details on the Privacy Policy and Terms of Use pages, accessible from the app menu within Teams.

Frequently asked questions

Can I work offline?

Opening a file requires an active connection because Banana is loaded dynamically. Once the file is open, local changes to the document do not require a network connection, but saving to the cloud does. If the connection drops while you are editing, you can still save the file to your device as a backup copy.

Does Banana Teams App replace the Banana Plus desktop application?

No. It is an additional way of working, designed for people who primarily use Teams. You can continue using the full Banana Accounting Plus desktop version for Windows, Mac and Linux.

Can I open .ac2 files with Banana Teams App and then continue working on them in the desktop version?

Yes. The .ac2 file format is the same. You can open a file in Teams, save it to OneDrive, and then open the same file in the Banana desktop version synchronised through OneDrive (or downloaded manually).

What happens if I close Teams while working?

The app detects when the tab is closed and warns you if there are unsaved changes, just like the desktop version. Automatic recovery mechanisms are also available for changes in more extreme situations.

Can I install the app on Teams mobile?

Yes, if your organisation also allows the app on Teams mobile. The experience is mainly designed for desktop computers, browsers and tablets. On smartphones, some operations may be less convenient because of the smaller screen size.

How many people can edit the same file at the same time?

Technically, several people can open the same file at the same time, and the app provides a visual notification through presence avatars. However, this is not real-time co-authoring like in Word or Excel: each user works on their own open copy and then saves the result to the cloud. If the remote version has changed in the meantime, the app displays a conflict dialog and allows you to overwrite the file, save a separate copy or cancel. We recommend coordinating with your team before making changes to a file that is already in use.

How can I report a problem or suggest an improvement?

Contact Banana.ch support through the contact form. When submitting your request, remember to mention that you are using the Teams App version so the support team can direct you to the right person immediately.

Conclusion

Banana Teams App brings the power of Banana Accounting Plus into the workspace you already use every day. Open your files wherever they are stored, save directly to the cloud and work on shared documents without exchanging emails: everything in one place.

If you have not installed it yet, try adding it to Teams today. For any questions or support, the banana.ch website is always available to help you.