# Upgrade QuickBooks Desktop
Source: https://www.desktopaccountingapi.com/docs/help/guides/upgrade-quickbooks/

> Keep the connection working when you install a new year's version of QuickBooks Desktop.

Installing a new year's version of QuickBooks Desktop, for example moving from 2023 to 2024, changes three things the connection depends on: the QuickBooks program, the company file format, and sometimes the permission QuickBooks gave the app. A few checks after the upgrade keep the connection running.

Monthly updates within the same year, the ones QuickBooks downloads by itself, do not need these steps.

## Before you upgrade

- Check that the new version is supported: QuickBooks Desktop Pro, Premier or Accountant 2018 or later, or Enterprise 2014 or later, US editions only. See [Requirements](https://www.desktopaccountingapi.com/docs/help/requirements/).
- Make a backup of the company file with **File › Back Up Company › Create Local Backup**.
- Plan the upgrade for a time when the app can wait. The connection pauses while QuickBooks is being installed and the file is updated.

## After you install the new version

1. **Open the company file in the new version as Admin.** QuickBooks asks to update the file to the new format. Accept. QuickBooks makes a backup and updates the file in place.
2. **Allow the app again if QuickBooks asks.** If the Application Certificate window appears for the app, choose **Yes, always; allow access even if QuickBooks is not running**, pick the same user under **Login as**, and click **Continue**, then **Done**. For this you need to be signed in as Admin in single-user mode.
3. **Check the Web Connector.** Open it from **File › App Management › Update Web Services** in the new QuickBooks. The app's row should still be there, with its box checked and **Auto-Run** on. If the row is missing, ask the app for a new setup link.
4. **Remove the old QuickBooks version.** Two installed versions confuse the Web Connector about which one to start. See [Keep one QuickBooks version installed](https://www.desktopaccountingapi.com/docs/help/guides/one-quickbooks-version/).
5. **Start the Web Connector from the new version's location**, if you had added a startup shortcut. See [Start QuickBooks and the Web Connector at sign-in](https://www.desktopaccountingapi.com/docs/help/guides/start-automatically/).

> **Caution:**
> If the file update saves the company file under a new name or in a new folder, the connection can no longer find it. Open the updated file in QuickBooks and see [Fix a moved, renamed or restored company file](https://www.desktopaccountingapi.com/docs/help/guides/moved-or-renamed-file/).

## Check that it worked

1. Close QuickBooks completely.
2. Do something in the app that needs QuickBooks.
3. The request succeeds, and QuickBooks starts in the background. If you chose "always allow", you may not see a QuickBooks window at all.

If the app reports that QuickBooks could not start, see [QuickBooks could not be started](https://www.desktopaccountingapi.com/docs/help/connection-errors/cannot-start-quickbooks/). If it reports that access is denied, see [QuickBooks denied access to the app](https://www.desktopaccountingapi.com/docs/help/connection-errors/access-denied/).

## When to contact the app's support team

Contact them if the connection fails after the upgrade and the pages above do not fix it. Send:

- the old and new QuickBooks version and year,
- the time and the exact message,
- a screenshot of the app's row in the Web Connector.

## Related pages

- [This QuickBooks version is not supported](https://www.desktopaccountingapi.com/docs/help/connection-errors/quickbooks-version-unsupported/)
- [Upgrade the Web Connector](https://www.desktopaccountingapi.com/docs/help/guides/upgrade-web-connector/)
- [Unable to cast COM object](https://www.desktopaccountingapi.com/docs/help/connection-errors/com-object-error/)