If you log into Firefox Sync using Account A on your computer, log out and then log into Firefox Sync using Account B, that should create a merged copy of your data (bookmarks, logins, etc) on Firefox. Then you can log out of Account B and go back into Account A. When you sync, that should send all of the data on Firefox to Account A, essentially creating a merged copy of all of the data on Account A. Once that's done, you could delete Account B.

Of course, you will want to check that all of the data is merged into Account A before deleting the other account. This could be done simply by logging into Account A on a new device to make sure that all of the desired data is synced.

Creating a local backup of your Firefox profile folder before deleting any accounts is also a good idea to be 100% sure that none of the data will be lost.

Hope this helps.

NOTE: Keep in mind that syncing large amounts of data may take some time. You may need to wait a while for the process to be completed and it's a good idea to press the Sync Now button more than once to ensure that all of the data is sent to the Firefox Sync servers.

You can install the About Sync extension in Firefox 72 and newer on desktop to check what data is stored on the Sync server via the about:sync page provided by this extension.

• About Sync https://addons.mozilla.org/firefox/addon/about-sync/

You may have to close and restart Firefox to access the about:sync page added by this extension (see the about:about page for available about pages).

You can open "about:" pages via the location/address bar

• "about:" is a protocol to access special pages

You’re the best! It worked, Thank you!!

I have almost the same problem. However one is an old SUMO account, and the other is a new Firefox account.

This method does not appear to allow the old SUMO account to be merged, which unfortunately has a different (now defunkt) email address.

The tool doesn't allow a (offer an option to) login to the old SUMO account which the normal login offers.

Any suggestions before the 30/March deadline?

Hi Philip Oakley

The About Sync tool uses the Firefox Account that is used to connect to Sync, this is or can be different than the email address you used in the past for this forum. The SUMO login page has a button link at the bottom to use a different Firefox Account if you are currently connected to Sync.

• https://accounts.firefox.com/oauth/signin

See this thread on the SUMO community discussions Forum Firefox Accounts final transition - now March 30th - SUMO community discussions Forums

• https://support.mozilla.org/en-US/forums/contributors/713942

Do you only have one SUMO account and was the new Firefox Account previously used for sync ?

Hi, I realised that what I needed to do was to convert my old SUMO account into a new Firefox account, but with a different user name - I used a spare ISP email address.

I was than able to do the login / out across the two accounts to merge the accounts (hopefully).

I've yet to do the account export check (as per link above) to confirm that I've picked up the older support links (which are still useful).

I just wanted to note the solution for anyone else who's bashing there head against the wall when there's a door right there... just to one side.

Only 2 days left to transfer those old SUMO accounts!

To answer the other question.

I think I'd created a new Firefox account based on an email notification or some auto web page on a Firefox update, and used my current email directly at that point. This left my old sumo account not being able to be upgraded to that new email address because it was already taken. (I also had the issue that my old SUMO used a now defunkt email address)

In a classic XY-problem I'd decided that it must be possible to merge the SUMO account directly with the other new Firefox account. No. I needed to transfer SUMO account to an alternate email address as a new Firefox account, and then merge.

I'm not sure if the chosen solution applies to my desire to merge Firefox Accounts resident on 2 different laptops? One is still running Vista, the other Win 7. Firefox recently stopped supporting Vista , and Win 7 is no longer being supported by Microsoft. I have established Sync on the Win 7 laptop but not on the Vista. I'd like to learn if I can still merge the 2 accounts, and if yes are there additional processes required before I can use the solution chosen? Thank you!

My experience was that both accounts need to accessible by "Sync" as it is only that application that can pull in both accounts and merge them.

This means that both accounts need to have been migrated to be full Firefox accounts with different user-names (email addresses), and hence accessible by Sync from the one machine that does the merge (and if both have the sync link then [I expect] it could be either).

It is important to check that the accounts you are looking at are of the types you expect. I found that the old SUMO accounts were only available when I accessed the support pages, while the new Firefox accounts appeared to be accessible as a _browser_ feature (i.e. the browser is logged into the account, no matter what page you are on, while the SUMO support account was on its server and could only be accessed from the support web page - a clash of mental models!)

On the Firefox about:sync page you can export your setting to a .json file (structured text), so you should export copies of the old and new stuff so you can compare later at your leisure.

Also make sure you have a list of the things you want to have copied, just in case you can get the data by differing means as a backup (e.g. browser bookmarks, page login names, saved passwords [held by the browser] :: list of support questions you asked, questions you answered [held by Mozilla, synced to your account & browser if sync enabled..];; etc.)