> ## Documentation Index
> Fetch the complete documentation index at: https://support.i.moneyforward.com/llms.txt
> Use this file to discover all available pages before exploring further.
# 5. Device Feature FAQ
> Frequently asked questions about device management.
The Device plan (paid) is required to use the device management feature. To request a trial, contact us via "**Ask a support representative directly**" in the chat.
## Device Registration and Updates
### An error appears during CSV import
Check the error message displayed. Then verify that all required fields are filled in by reviewing the [**Registration Template**](/en/it-management/device/dwrsgbckjp-device-csv#registration-template). Also review the [**CSV Import Precautions**](/en/it-management/device/dwrsgbckjp-device-csv#csv-import-precautions).
If the issue persists, contact us with the error details.
### I want to register the status "Pre-use"
The status "Pre-use" does not appear in the "Change Assignment and Status" screen. For devices in **Pre-use** status, select the status "In Use" and set a future date as the assignment date. After saving, the status changes to "Pre-use," and on the assignment date it automatically changes to "**In Use**."
### I cannot register a management field called "Device Age"
Register a "Purchase Date" in the "Edit Device Information" screen. The "Device Age" is then calculated automatically from that date.
### Handling devices without an asset number
If no asset number has been assigned, register the device using a combination of the device name and a sequential number.
Example: mouse0001
### I want to manage devices not linked to an employee, such as a conference room monitor
You can register a device without linking it to an employee (email address). By setting a location, you can manage devices such as monitors in conference rooms.
### I want to clear the usage history of a device
Go to Devices > select a device > "Usage History" under the "Info" section.
When you [register a device](/en/it-management/device/tmkn2wxi35-manage-device), its status is set to "In Stock." Then use \[Change Assignment Status] to assign the correct status and user, and use \[Add History] to record the history. Once history is added, you can view details via "**See more**" in the lower left.
Usage history entries can be \[deleted] from the three-dot menu \[**︙**], but **one record of usage history always remains**.
To delete the remaining record as well, use \[Add History] to register the "Status" of the history you want to keep.
※ When changing an assignment, using \[Unassign] removes the assigned user information.
## MDM Integration
### I want to stop MDM integration
Go to Integrations > Status and \[Delete] the relevant service name or workspace.
### Two devices with the same serial number were registered
This happens when two devices with the same serial number temporarily exist in the MDM. Follow these steps:
1. Delete the newly added device (with the duplicate serial number) via the MDM integration.
2. Run a sync with the MDM and confirm that the existing record is synced (merged) from the MDM.
### I deleted a device from MDM
When you delete a device from MDM, the MDM integration is disconnected.
The device remains on the device screen, but the MDM icon, links, and MDM-related fields no longer appear after the integration is disconnected.
※ Deleting a device from MDM does not change the status on the device screen.
### MDM was uninstalled from the device
Whether the device disappears from MDM after uninstalling the MDM software depends on the MDM's behavior.
If the device remains in the MDM tool after the MDM software is uninstalled, the integration stays active.
If the device is removed from the MDM tool, the MDM integration is disconnected.
In either case, the status does not change and the device remains on the device screen.
### The device is not linked after MDM integration
When merging with a registered device via MDM integration, the `serial number` is used as the **merge key**.
If the device is not merged after MDM integration, use one of the following approaches:
| Method | Description |
| -------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------- |
| Register an email address on the MDM service side. | After registering the email address in the MDM service, delete the MDM integration and reconnect it. |
| Register an email address in the device ledger. | See [\[Device\] How to Create a Device Ledger CSV for Import](/en/it-management/device/dwrsgbckjp-device-csv) for instructions. |