In adding Claude in Excel

Question

I am logged in to Excel on my Microsoft 365 account, but I can't sign into the store for an add-on. How do I get the add-on if the system is broken?

Answer 1

Hi RR,

Is Microsoft Office provided by your Company where you work? This may explain why Add-ins store isn't available?

I’m eager to hear back and work together to find a solution.

Answer 2

Use Excel without the Store sign-in by confirming the add-in platform works and that sign-in is fixed at the Office level.

1. Verify Excel add-ins work in general
   • In Excel, go to File > Get Add-ins or Home > Add-ins > More Add-ins.
   • If the Office Add-ins dialog does not load or stays blank, there may be a sign-in or network issue affecting all Office add-ins, not just the Store.
2. Make sure the correct account is used
   • Office add-ins use the same identity as Office.
   • Sign out of Excel completely, then sign back in with the Microsoft 365 account that has the subscription.
   • If there are multiple accounts, explicitly sign out inside any add-in task pane and sign back in with the correct one, as stored browser credentials can cause wrong-context sign-in.
3. Check for Excel add-in sign-in issues
   • If the Excel add-in sign-in dialog is blank or errors, network or authentication endpoints may be blocked.
   • Ensure required URLs for Office add-ins and Microsoft Entra sign-in are reachable from the device (for example https://appsforoffice.microsoft.com and https://login.microsoftonline.com). If a proxy or firewall is used, these endpoints must be allowed.
4. Use My Add-ins if the add-in is already assigned
   • If the Claude add-in was previously acquired or assigned by an admin, open it without going through the Store:
     1. In Excel, select Home > Add-ins > More Add-ins.
     2. In the Office Add-ins dialog, select the My Add-ins tab.
     3. Double-click the add-in (or select it and choose Add) to start using it.
5. If the Store remains inaccessible
   • If the Office Add-ins Store cannot be reached at all but Excel itself is signed in, this is typically an environment or network issue rather than Excel being “broken.”
   • In that case, an administrator can deploy or assign the add-in centrally so it appears under My Add-ins, bypassing the need for the user to browse the Store directly.

If none of these steps allow access to the Store or to the add-in under My Add-ins, the issue is likely with the Office sign-in or network configuration and should be escalated to the organization’s IT or Microsoft Support with details of any error dialogs seen when opening Get Add-ins.

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References:

• Get an Office Add-in for Excel
• Office Store FAQ
• Office integration FAQ
• What you can do in the Microsoft 365 apps on mobile devices with a Microsoft 365 subscription
• Can't sign in to microsoft 365 desktop apps - Microsoft Q&A
• Cannot sign in to Office apps - error 0x800704cf - Windows authentication broken - Microsoft Q&A
• MS365 products not signing in as even when internet connection is available - Microsoft Q&A