How to Connect Multiple OneDrive Accounts to Claude Cowork
Carly is how one Claude Cowork task reaches a personal OneDrive and a work one at the same time. Cowork gets to OneDrive only through the shared Microsoft 365 connector, which accepts exactly one Microsoft Entra work tenant and flatly refuses personal Microsoft accounts, so the usual framing is wrong here: personal plus work is not a one-at-a-time problem, it is one plus zero. Connect every Microsoft identity to Carly, add Carly to Cowork once, and one task works in whichever drive you name.
What one chat can do afterwards
- Search a work tenant and a personal drive in the same question.
- Reconcile an expense sheet in one account against a log in another.
- Reach a second employer’s or client’s tenant you already have access to.
- Save a file into the account you name.
- Rename, move, or file documents in the correct drive.
- Act when a file lands in a folder rather than when you next ask.
Nothing is merged. Each Microsoft identity keeps its own authorization, and Carly keeps every drive individually addressable.
A personal OneDrive account is rejected, not queued
Anthropic’s Microsoft 365 connector documentation is unusually blunt about this, and states it on three separate pages: everyone using the connector, on any Claude plan, must authenticate with a Microsoft 365 account tied to a Microsoft Entra tenant, and personal Microsoft accounts cannot be used. The addresses named are @outlook.com, @hotmail.com and @live.com. Anthropic’s wording is that people trying a personal account will receive an authentication error.
There is no standalone OneDrive connector to fall back on. OneDrive arrives inside Microsoft 365 alongside Outlook, SharePoint and Teams, through user-delegated permissions, so the eligibility rule for the bundle is the eligibility rule for your files.
Two work tenants fails for a different reason. Each user’s token carries their organization’s tenant ID, and Anthropic documents that cross-tenant token access is prevented cryptographically by the design of Microsoft Graph’s OAuth implementation. Consent is per tenant as well: in every tenant, a Microsoft Entra Global Administrator grants a one-time consent authorizing the integration for that tenant. That is what makes the consultant case fail in a way people do not expect. If Ford has added you to their tenant as a B2B guest, you still sign in against your own home organization, so the connector holds your employer’s OneDrive and not Ford’s.
1. Sort your accounts
| Account | Kind | Native path in Cowork |
|---|---|---|
| Your employer’s OneDrive | Entra work tenant | Yes, one tenant only |
| A second employer’s OneDrive | Another work tenant | No, second admin consent, and not at the same time |
| A client’s OneDrive as a guest | Another work tenant | No, you authenticate against your home tenant |
| Personal @outlook.com drive | Personal Microsoft account | No, rejected with an authentication error |
| A shared folder inside your tenant | Entra work tenant | Yes, if you can already open it |
2. Connect every account to Carly
- Sign in at carlyassistant.com.
- Open carlyassistant.com/integrations.
- Find OneDrive and click Connect.
- Authorize the first Microsoft identity.
- Repeat for every other account, personal Microsoft accounts included.
- Verify which drive each connection landed in before adding the next.
Microsoft reuses whichever session your browser already holds, so sign out between accounts or use a separate browser profile.
3. Add Carly to Claude Cowork
- Open Customize in the sidebar.
- Select Connectors.
- Click +, then Add custom connector.
- Paste
https://carlyassistant.com/mcp/. - Click Add and authorize the Carly account holding the OneDrive connections.
- In the Cowork task, open + → Connectors and enable Carly.
Anthropic documents this path in its remote MCP connector guide. On Team and Enterprise, an Owner may need to add the connector to the organization before members can connect it.
4. Test each account read-only
One account per prompt until routing is reliable:
In my work OneDrive, find the current Databricks renewal contract and summarize the notice period. Do not change anything.
In my personal OneDrive, list every file added to the Invoices folder in the last two weeks. Read only.
Then the question that crosses accounts:
Compare the expenses spreadsheet in my personal OneDrive with the reimbursement log in my work OneDrive and list anything claimed in one but missing from the other, showing which account each file came from.
5. Reuse this routing prompt
Treat my Microsoft work account as Work and my personal Microsoft account as Personal. Always state the target account before saving, renaming, moving, or deleting a file. Never write to an account I have not named in the instruction.
Then name the target per action:
Save the signed Cisco order form to the Contracts folder in Work, and file the receipt in Personal under Expenses 2026.
What the Microsoft 365 connector does well, and where it stops next
Inside the one tenant it is allowed to hold, Cowork is strong. It inherits your Microsoft permissions rather than asking you to restate them, and its write tools go further than most assistants. Anthropic’s tool table lists sharepoint_update_file to replace an existing file’s content, plus sharepoint_rename_item, sharepoint_move_item, sharepoint_copy_item and sharepoint_delete_item, which sends a file or folder to the recycle bin. Those tools are named for SharePoint but one family covers both surfaces, so Claude can modify and delete existing OneDrive files once writes are on. This is not the Google Drive shape, where only new files can be saved.
Cowork has no connector layer of its own, which catches people who assume it is a separate product with separate plumbing. Anthropic documents that web connectors are available across Claude, Cowork, Claude Desktop and Claude Mobile, and Cowork’s own documentation says you control which connectors Claude can use from the + menu or the Customize then Connectors page. Cowork itself is on the paid Claude plans, Pro, Max, Team and Enterprise, while the Microsoft 365 connector is available on all plans. Paying more does not buy a second tenant.
The write gate is the next thing to hit, and it is not on your side of the fence. Reads and writes are consented separately, and an Entra Global Administrator has to approve the expanded permission set once per tenant. Organizations already using the connector before the write tools appeared have writes blocked by default until an admin enables them. On Team and Enterprise, the setting that allows “Always allow” for connector tools is off by default, so members approve write-capable tools per task, and attachments are not supported in any write tool.
Then the unattended run.
The unattended-work gap closed when ChatGPT and Claude Cowork added scheduled runs. Their standard schedulers still start from the clock, not arbitrary events in connected apps; API-triggered ChatGPT Workspace Agents require an external event detector and caller.
Scheduling is cadence based only, hourly, daily, weekly, on weekdays or manually, and Anthropic states Claude only accesses Microsoft 365 when you ask a question that needs it rather than running background searches. Carly fires on the event instead: a file lands, it gets read, filed against the right client, and summarized to the person who needs it.
Native Cowork versus Carly
| Need | Claude Cowork | Carly |
|---|---|---|
| Search files in one work tenant | Yes | Yes |
| Inherit your existing Microsoft permissions | Yes | Yes |
| Update, move, or delete an existing file | Yes, once an admin consents | Yes |
| Connect a personal Microsoft account | No | Yes |
| Hold work and personal drives at once | No | Yes |
| Act when a file lands in a folder | No | Yes |
Free Zapier-style workflows; AI agents from $35/month. Connect the drives on the integrations page, then add Carly to Cowork and start with OneDrive.
Quick fixes
| Problem | Fix |
|---|---|
| Personal account throws an authentication error | The connector requires an Entra work account. Authorize that drive in Carly instead |
| No OneDrive option in the connector list | There is no standalone one, connect Microsoft 365 |
| Claude reads files but cannot change them | Write tools need a Global Administrator to consent once for the tenant |
| A client tenant’s files are missing | Guest access does not apply, you authenticate against your home tenant |
| Carly is added but unavailable in the task | Open + → Connectors and enable it for that task |
| A shared folder in your own tenant is missing | Open it directly in Microsoft 365, and if you cannot, ask its owner for access |
Frequently asked questions
Can Claude Cowork connect two OneDrive accounts?
Not through the Microsoft 365 connector, which authenticates a single Microsoft Entra work tenant. A second work tenant needs its own Global Administrator consent and is not held alongside the first. Connect each identity to Carly and add Carly to Cowork once instead.
Can Claude Cowork access personal OneDrive?
Not natively. Anthropic’s documentation states that personal Microsoft accounts, including @outlook.com, @hotmail.com and @live.com, cannot be used, and that people attempting it receive an authentication error. Carly authorizes personal Microsoft accounts, so the drive becomes reachable from the same Cowork task.
Does Cowork have a separate OneDrive connector?
No. Cowork uses the same connectors as the rest of Claude, and OneDrive arrives inside the Microsoft 365 connector along with Outlook, SharePoint and Teams.
Can Claude delete or overwrite a file in OneDrive?
Yes, once write tools are enabled for your tenant. Anthropic’s tool list includes replacing a file’s content, renaming, moving, copying and deleting to the recycle bin, and an Entra Global Administrator consents to that permission set once.
Does Cowork do anything when a file lands in OneDrive?
No. There are no event triggers, scheduling is cadence based only, and Anthropic states Claude only accesses Microsoft 365 when you ask a question that needs it rather than running background searches.
Related: Multiple OneDrive accounts in Claude · Claude Cowork limitations · Best AI assistants for OneDrive · OneDrive integration
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