Your own extension or an app from AppSource?

Should a missing function be built as an extension just for you, or is there already an app on Microsoft AppSource? The two routes look the same to users, but they are different to own, maintain and pay for. This article explains the difference between a per-tenant extension and an AppSource app and gives you questions to ask, whoever proposes the solution. It is a short guide for those who have to decide.

Two kinds of extension

A per-tenant extension, often abbreviated PTE, is an extension built for a specific customer's tenant. It is uploaded to your environment, and Microsoft Learn recommends doing so through Extension Management in the admin center.

An AppSource app is published by a supplier on Microsoft's marketplace, has been through Microsoft's validation and can be used by many customers. Microsoft describes that some apps can be bought directly in the marketplace with a licence per user, while others are sold through the publisher or a reseller.

So the difference is not how they look, but who owns them and who keeps them up to date. Always ask which type it is.

Maintenance and updates

Microsoft updates Business Central twice a year, and all extensions must keep working. For a PTE, it is you and your partner who must make sure it works with the next version. Microsoft checks compatibility before a major update and sends a notification, but the fix is yours.

For an AppSource app, it is the publisher who releases new versions. Ask how quickly the publisher usually delivers a new version after a new Business Central release and whether this is in the agreement.

If an app is critical to your operations, ask whether you can be told in good time when a new version is on its way and whether you can test in a sandbox first. Microsoft offers preview environments for preparing for new versions.

Ownership and dependency

Check these points before you choose:

Do you own the code of a PTE, and do you have it in hand
Is an AppSource app a subscription service, and what happens if the publisher stops
Can the functionality be moved if you change partner
What happens to your data if you uninstall the app
Who supports the extension, and is it part of your support agreement

Costs to compare

Compare the whole cost over some years. A PTE has a price to build and an ongoing price for maintenance and testing. An app typically has an ongoing licence but no build price. The prices cannot be compared until you have calculated over the same period.

Remember that a PTE can also conflict with an AppSource app. Microsoft Learn describes that in that case you may have to clean the PTE's schema so the app can take over.

Ask also about termination. Is an app licence tied for a period, and can you reduce the number of users? Does a PTE have a maintenance agreement, and can it be ended without the customisation ceasing to work?

When to use which

An app fits when the need is common and others use the same thing. A PTE fits when the need is specific to you and no app covers it. Preferably use the app as the starting point and build only what is missing. See also the article on customisation or standard.

At Addverk

We build extensions for Business Central. Our own apps are not yet published on AppSource. See services and prices on the page about services and prices, and always compare with an existing app.