When you are working in Autodesk Civil 3D 2026, and you open a drawing that is stored in Forma Data Management, the document is automatically locked so no one else can edit it while you have it open.
Locking in Civil 3D
When you open most types of unlocked documents from Forma Data Management in Autodesk Civil 3D 2026, they are automatically locked so that only you can edit them. A document is locked regardless of the method of opening it (such as opening a document from the Start tab or from the connected drive in Windows Explorer).
While you have the document locked, your changes will be saved to Forma Data Management, and other team members working in the Forma Data Management project can open the document read-only.
When you close the document, the document will be unlocked and someone else can open it for editing.
When you save a new drawing to Forma Data Management, it is locked automatically after the synchronisation process has been completed.
The following icons are displayed on the Prospector tab of Toolspace indicate the locked status of open drawings:
: The drawing is open for edit and is locked by you.
: The drawing is open read-only and is locked by someone else.
: The drawing is open read-only and is not locked by anyone else.
The following icons are displayed on the Forma Data Management page of the Start tab:
-
: The drawing is locked by you. When you open a document to edit it, the document is locked and this icon is displayed in the Locked State column.
: The drawing is locked by someone else.
- If the drawing is not locked, no icon is displayed.
Files that require manual locking
Automatic locking and unlocking is not supported for survey databases. You need to manually lock and unlock these files when working with them to avoid editing conflicts. See the following section for information about manual locking.
Locking in previous versions of Most of the cloud collaboration work for the 2022 release revolves around performance, stability and consistency improvements
If you are working in Civil 3D 2020.1 or a previous version of Civil 3D, or any version of AutoCAD or an AutoCAD-based product, locking is not automatic when you open a drawing that is stored in Forma Data Management.
Before editing a document, you should manually lock it before editing it. If you don't lock it, someone else could overwrite your changes. You can lock a document on a connected drive, or you can lock it in Forma Data Management.
When you save a new drawing to Forma Data Management, you should manually lock it before continuing to work on it so someone else cannot overwrite your changes.
After editing and saving the document, you can check the document version shown in Forma Data Management and review the changes in the Forma Data Management Viewer. For more information, see To Use Forma Data Management Viewing and Markup Tools for Civil 3D Drawings. After you have confirmed the changes are uploaded, you need to manually unlock the document so other team members can edit it.
To manually lock or unlock a document in Forma Data Management
- Open Forma Data Management and navigate to the document location.
- Select the tick box next to the document and then click the lock icon
or the unlock icon 
.
For more information, see Documents in the Forma Data Management Help.