Business Central stores document attachments in the database by default. As your organization accumulates invoices, contracts, and scanned documents, these attachments can consume a significant portion of your 80 GB default database capacity.
Starting with 2026 release wave 1 (version 28.0), you can store attachments externally in Azure Blob Storage, Azure File Share, or SharePoint. Once configured, new attachments are saved to your external storage automatically. Users continue to attach, view, and download files the same way as before.
You are responsible for managing and backing up files in external storage. Microsoft does not include externally stored files in Business Central environment backups.
Supported Storage Providers
Business Central supports three external storage types out of the box:
| Provider | Use case |
|---|---|
| Azure Blob Storage | Cost-effective storage for large volumes of files |
| Azure File Share | Shared file storage with folder structure |
| SharePoint | Document management with collaboration features |
The external file storage framework is extensible. Partners can add other providers through extensions.
Set Up an External File Account
Before offloading attachments, create an external file account that stores the connection details for your storage service.
- Search for External File Accounts using
Alt + Q. - Select Add a file account to start the setup wizard.
- Choose the storage type: Azure Blob Storage, Azure File Share, or SharePoint.
- Enter the connection details for your chosen provider.
Azure Blob Storage
- Account Name: A friendly name for use within Business Central.
- Storage Account Name: The name of your Azure storage account.
- Authorization Type: Choose between a Shared Access Signature (SAS) token or a shared account key.
- Secret: Paste the SAS token or access key.
- Container Name: The blob container where attachments will be stored.
Azure File Share
- Account Name: A friendly name for Business Central.
- Storage Account Name: Your Azure storage account name.
- Authorization Type: SAS token or shared key.
- Secret: The SAS token or access key.
- File Share Name: The Azure Files share name.
SharePoint
- Account Name: A friendly name for Business Central.
- Tenant ID, Client ID, Client Secret: From your Microsoft Entra ID app registration that has access to the SharePoint site.
- SharePoint Name: The domain or site name.
- Base Relative Folder Path: The document library and folder path. Start from the site root, for example
Shared Documents/Attachments.
- Select Next, review the settings, and select Finish.
You can repeat these steps to add multiple storage accounts if needed.
Enable External Storage for Document Attachments
After creating a file account, assign the document attachments scenario to it.
- Search for File Scenario Assignment using
Alt + Q. - Select Assign scenarios.
- Locate the file account you want to use and select OK.
- Select the file account line, then choose Assign Scenarios or Edit.
- Select the Document Attachments - External Storage scenario and confirm.
- The External Storage Setup page opens. Configure the following:
- Turn on the Enabled toggle. Business Central will show a warning that external storage is your responsibility. Select Yes to proceed.
- In the Root folder field, select an existing folder in your external storage. Business Central creates subfolders automatically, organized by environment, company, and table.
- Turn on Delete External File on Attachment Delete if you want Business Central to remove the file from external storage when someone deletes the attachment record. If disabled, the file remains in storage but the link in Business Central is removed.
- Select Close.
From this point on, any new attachment added to a record in Business Central is stored in the external location.
Migrate Existing Attachments
Only attachments added after enabling external storage go to the external location. Existing attachments remain in the database.
To move existing attachments to external storage:
- Go to the External Storage Setup page (or the File Scenarios page).
- Select the Storage Sync action.
- Specify the direction: from Business Central database to external storage.
- Run the operation.
You can also use this action in reverse if you need to stop using external storage and move all files back into the database.
How Attachments Work After Setup
The day-to-day experience does not change for users:
- Attach files using the Attachments FactBox on any record, or the Attachments action on document lines.
- Open or download attached files the same way. Business Central retrieves the file from external storage automatically.
- Delete attachments from the FactBox or the Document Attachments page.
Behind the scenes, Business Central appends a unique ID to each file name in external storage to prevent naming conflicts. The attachment title shown in Business Central keeps the original file name.
If a file is deleted directly from external storage (outside Business Central), the attachment link in BC will show an error when someone tries to open it.
Copy Company and Environment Considerations
When you use Copy Company or restore an environment backup, attachment records (metadata) may be copied, but the files still point to the original external storage location.
To migrate files to the new environment or company folder:
- Go to the External Storage Setup page.
- Select the Migrate Files action.
- This copies all document attachments from the previous environment or company folder to the current one in external storage.
Browse External Storage from Business Central
You can verify that files are stored correctly using the built-in storage browser.
- Search for External File Accounts using
Alt + Q. - Select your storage account.
- Choose the Storage Browser action.
The External Storage Browser page shows folders and files in your connected storage. You can upload, download, delete files, and create new folders from this page.
For a broader overview of all new features in this release, see What’s New in Business Central 2026 Release Wave 1.