Every attachment your team adds to a Business Central record — a scanned invoice, a vendor contract, a delivery photo — is quietly increasing the size of your database. Most admins don’t notice the impact on Business Central storage until they’re already close to capacity.
Business Central customers have 80 GB of database storage capacity, shared across environments in the tenant. In document-heavy operations, attachments can eat through that allocation faster than other data types. BC28 introduces a native external file storage feature — no code required — that enables Business Central SharePoint integration for new attachments, with Azure storage also supported.
This post walks through how the feature works, the step-by-step setup process, what to know about existing attachments, and the key configuration decisions to make before you go live.
By default, Business Central attachments — from sales orders to vendor cards — are stored as a Media data type directly in the Business Central database. This is invisible to users, but attachments can accumulate quickly in environments that handle a lot of invoices, purchasing documents, or project files. Business Central customers start with 80 GB of base database storage capacity shared across environments in the tenant, with additional capacity per license (3 GB per Premium, 2 GB per Essential, 1 GB per Device). Attachments can quietly consume a large share of that over months or years.
Business Central external file storage addresses this by redirecting new attachments out of the database and into an external location. Three storage targets are supported out of the box:
(Additional providers such as SFTP or OneDrive are possible only via a custom/partner extension — they are not native targets.)
Once configured, Business Central document attachments land in the external location and are accessible from within BC exactly as before and users see no difference.
No AL customization is required. The feature was introduced in BC27 but had reliability issues with some M365 license configurations; BC28 resolves this.
Setting up Business Central SharePoint integration requires a one-time app registration in Microsoft Entra ID and a few minutes in BC’s Assisted Setup wizard. No AL development is involved.
Step 1: Register an app in Microsoft Entra ID. Create an app registration that can access the SharePoint site you plan to use and generate a Client Secret. Note your Tenant ID, Client ID, and Client Secret; you'll need them when configuring the SharePoint external file account in Business Central.
Step 2: Configure the account in Business Central. Search for External File Accounts (also accessible via Assisted Setup) and add a new file account. Select SharePoint, enter your Tenant ID, Client ID, Client Secret, SharePoint name or site information, and Base Relative Folder Path (e.g., Shared Documents/BC). Use Storage Browser to verify the connection before proceeding.
Step 3: Enable the Document Attachments scenario. Open File Scenario Assignment, choose Assign Scenarios and assign the Document Attachments scenario to the appropriate external file account. Enable the toggle, confirm the responsibility warning, and select a Root Folder. BC will automatically organize subfolders by environment, company, and table.
“When this feature is enabled, files will be stored outside the Business Central service boundary. Microsoft does not manage, back up, or restore data stored in external storage.” — BC28 setup warning. Configure SharePoint retention policies before enabling in production.
Two additional things to decide before going live:
First, existing attachments already in BC do not migrate automatically — only new attachments after setup will go to SharePoint. A Storage Sync tool is available to migrate historical files manually; plan time for this if reducing current database size is the goal.
Second, the Delete External File on Attachment Delete toggle determines whether deleting an attachment in Business Central also deletes the external file from SharePoint. Choose deliberately based on your retention policy.
Database bloat from attachments is one of the most common — and most avoidable — capacity issues in Business Central environments. BC28 now offers a native, no-code solution that uses external storage such as SharePoint or Azure and is invisible to end users once configured. The Entra app registration is the most involved part of setup, and even that is a one-time task.
Start in a sandbox, verify the Storage Browser connects, confirm the Document Attachments scenario appears, and then roll it out to production. If you have years of existing attachments you want to move, plan the Storage Sync migration separately. The database growth problem won’t fix itself, but Dynamics 365 Business Central SharePoint integration now provides a supported, standard way to stop it.
Want help assessing your environment or setting up external attachment storage in Business Central? Talk to a Clients First Business Central expert
Yes. Business Central's external file storage functionality can be configured so new document attachments are stored externally in SharePoint instead of consuming Business Central database capacity. Users can continue accessing the attachments through Business Central.
No. Only new attachments added after configuration are stored externally. Files already in the database stay there. You can use Storage Sync to migrate historical files manually, but this should be tested in a sandbox before running in production.
No. Attachments still appear on the Attachments tab in the FactBox panel exactly as before. The only difference is where the file physically lives. No retraining, no workflow changes, no visible UI differences for end users.
That depends on how Delete External File on Attachment Delete is configured. Administrators should decide whether the external file should also be removed when its Business Central attachment is deleted, based on the organization's retention requirements.