How to fix invalid package identity and publisher errors in the Microsoft Store

The errors and what each one means

The reserved-name message is quoted from Microsoft's submission errors page. The identity name and publisher messages are quoted from developers' posts on Microsoft Q&A, with their own values in them, so yours will show your names. We couldn't find a published wording for the family name and display name errors, so those rows describe the problem instead of quoting it.

Where Partner Center shows your identity

Open your app in Partner Center, expand Product management in the left menu and select Product identity. Microsoft's identity docs list three values your package manifest must include:

• Package/Identity/Name
• Package/Identity/Publisher
• Package/Properties/PublisherDisplayName

Together they put every package of your app in one package family. The same page also shows the Package Family Name and the Package SID, which aren't in the manifest. Windows makes the family name from the package name and a 13-character publisher ID derived from Publisher, like Microsoft.Windows.Photos_8wekyb3d8bbwe, so it's right as soon as Name and Publisher are.

If the page offers to create an identity instead, your app doesn't have one yet. Microsoft says you need to reserve a name to create it, and that name is the one your package has to use.

Where each value goes in AppxManifest.xml

Name and Publisher are attributes of the Identity element, next to Version and ProcessorArchitecture. PublisherDisplayName is its own element inside Properties. DisplayName, the app name people see, sits next to it and isn't part of the identity check described here.

<!-- AppxManifest.xml (Package.appxmanifest in Visual Studio) -->
<Package ...>
  <Identity
    Name="12345Contoso.NotesApp"
    Publisher="CN=12345678-1234-1234-1234-123456789ABC"
    Version="1.4.0.0"
    ProcessorArchitecture="x64" />
  <Properties>
    <DisplayName>Contoso Notes</DisplayName>
    <PublisherDisplayName>Contoso</PublisherDisplayName>
    ...
  </Properties>
  ...
</Package>

The values above are made up. Microsoft's package requirements say values in the manifest are case-sensitive and spaces and other punctuation must match too, so paste them rather than retyping them.

To see what a package you already built contains, unpack it with MakeAppx from the Windows SDK, or install it and ask PowerShell. If the name or publisher printed there differs from Product identity, the fix is in your build config, not in Partner Center.

# Unpack a built package and read its manifest
makeappx unpack /p NotesApp.msix /d unpacked
type unpacked\AppxManifest.xml

# Or, after installing it, ask Windows
Get-AppxPackage *NotesApp* | Select Name, Publisher, PackageFamilyName

How common packagers set the identity

In Visual Studio, Microsoft says to stay signed in with the account tied to your developer account while you package, because the identity details are added automatically and leaving them out can cause upload failures. On Microsoft Q&A, the publisher error has come from Visual Studio using a locally cached test certificate. Making a new test certificate on the Packaging tab, with your publisher ID as the common name and without the CN= part, fixed it there.

The framework guides have the full config for each tool: publishing an Electron app covers the appx section and the applicationId rule for names that start with digits, and publishing a Flutter app covers msix_config and the Store build.

When the error shows up on an update

If the first version went through and an update fails, something in the build changed. It might be a CI job that signs with a different certificate, a config for sideloading that sets its own publisher, or a build that picked up a different name than the one on Product identity. Compare the unpacked manifest with Product identity again. Our guide to updating an MSIX app covers the version rules and the other upload errors you can hit on an update, and failed certification covers problems found after the upload goes through.

How StoreFast checks the package name before upload

When you choose an .msix in StoreFast, your browser reads the AppxManifest.xml inside it before anything uploads. StoreFast compares the Name on the Identity element with the package identity name Partner Center reports for the app, exactly as written. If they differ, the check shows both, like "Package name is MyApp, but this app expects 12345Contoso.MyApp", and Continue stays off. The same screen checks that the version is higher than the live one and ends in .0.

StoreFast doesn't compare Publisher or PublisherDisplayName yet, so Partner Center can still reject a package whose name is right and whose publisher isn't. It takes a single .msix and stops on a bundle. The steps are in the publishing docs.

Questions

What does "Invalid package identity name" mean?

Partner Center read the Name attribute of the Identity element in your package and it isn't the one reserved for this app. The message shows what it found and what it expected, like Invalid package identity name: MyApp (expected: 12345Contoso.MyApp). Copy the expected value into your manifest or packaging config and build again.

Why does Partner Center say my package publisher name is invalid?

The Publisher attribute in your manifest has to be the CN=... value from the Product identity page, and it usually comes from your signing certificate. A package signed with your own certificate or a temporary test certificate carries that certificate's subject instead. Set the publisher to the Partner Center value. You don't need your own certificate for a Store package, since Microsoft re-signs it.

Can I set the Package Family Name myself?

No. Windows builds it from the package name and a 13-character ID worked out from the publisher, so it's correct once Name and Publisher match Partner Center. If the family name is wrong, one of those two is wrong.

Is the package name case-sensitive?

Treat it as case-sensitive. Microsoft's Store docs say manifest values are case-sensitive and spaces and punctuation must match too, so paste them exactly as Partner Center shows them.

I reserved a new name for my app. Which one goes in the package?

The one shown on the Product identity page. Microsoft's fix for the reserved-name error is to confirm the identity there and, if you want to use a different name, reserve it under Manage app name reservations first.