Trello Outlook Calendar Addon

Trello Outlook Calendar Addon


This project is no longer being developed. Thanks for all your support.

Update (28th October 2014): This project is no longer being developed. I currently have a backlog of paid projects that will have my full attention for the foreseeable future. I would like to thank everyone that has downloaded and supported my addon. The addon will still continue to function as usual, I may make minor bug fixes if anything in the Trello or Outlook API changes, however there will not be any new features added. As usual feel free to leave any questions, comments or issues in the comments below.

Update (16th May 2014): While this addon is free for personal and commercial purposes, a lot of my “after hours” time has been put into supporting, bug fixing and adding features. I would greatly appreciate any donations (below) and feedback! I have started rewriting from the ground up, any feature requests are welcome via comments. Lastly, thanks for the continued support!

Recently I have started using Trello, a free web-based project management application. I like how easy it is to use, however I wanted a solution that would allow me to sync my Trello cards that had due dates, to a caledar in Outlook (then having it on Exchange also). I had a quick Google, but couldn’t find anything that would fit my needs, so the programmer in me said, “Why not create one!?!”. The main things I needed this solution to accomplish was:

  • Authenticate with Trello
  • Get a list of the users boards
  • Allow the user to select the boards to be synced
  • Create an Outlook Appointment item for each card using the data pulled from Trello
  • Update card if the appointment already exists
  • Push updates to Trello (Update card name, due date, description etc…)

So almost 1000 lines of code later and I have my first Outlook Addon, although at the moment I only have it pulling from Trello, I’m about to start looking at the push side to update cards. The source code is available on GitHub or download the installer below. I am still developing this addon, please look at the development board for more information.

This addon is supported via your donations, if you have found it useful, please consider supporting it by donating

Total Raised: $30.00

Many thanks to the following people:

Christopher Hunter
Sateesh B Pedagadi
Christian Fingerhut

Last updated: 08/12/2014

Change Log

Version (Latest)

  • Added option to specify the default “Reminder Time”
  • Added “Manual Authentication” option for users with Internet Explorer 6, 7 and 8 as Trello has dropped support (Found under File -> Trello)


  • Fix problem when text had UTF-8 characters


  • Reduce the number of calls to Trello
  • Added a background timer to sync at a regular interval


  • Inital Release

Bugs and Improvements

Found a bug or want to request an improvement or feature? Use the contact form to let me know or leave it in the comments below! Want to fix the bug yourself, even better! The source code is available on GitHub.


  1. Hi,
    This addon seems great. Cool work.

    • I was able to down load the initial version, but not the second. In outlook there is not a Trello button to configure just a move to trello folder that does nothing. Your patience is appreciated.

      • Bradly Sharpe

        Hi, I have fixed the download link for the current release, sorry about that! I will also shoot you an email to troubleshoot your problem :)

        • I will definitely send some money your way for your hard work assuming this works;) Not tried it yet. (nothing huge as I am not rich but a tip though!

  2. Outlook says Authorise Trello, How do I correct it? Is there a config file or something? Thanks.

    • Bradly Sharpe

      Hi Justin,

      Under the file menu there should be a “Trello” menu, from here you can Authorise the application

  3. Hello,

    I can authorize Trello in Outlook just fine, but when i goto calendar and press Configure from ribbon, nothing happens?


    • Bradly Sharpe

      Hi Timppa,

      I will email you to sort this problem out and post the results here in case anyone else has the same problem.

      • Bradly Sharpe

        Problem has been fixed with version – The problem was the encoding of UTF-8 characters.

  4. Hi Bradly, I installed v0.2.0.4 and config works fine, but when I hit Sync, nothing seems to happen (I have a couple cards with due dates this week… expected to see an appointment show up in Outlook).

    Thanks for the help, and thanks for creating this.

    • Bradly Sharpe

      Problem was resolved by un-ticking the “Cards assigned to Me” check box as the cards were not assigned to him.

      • I had the same problem. I downloaded the most recent version of the Add-On, was able to configure it, and then when I clicked “Sync” nothing happened. I did not tick “Cards assigned to me.”

        • Bradly Sharpe

          Hi Jessica, Have sent you an email to try and resolve the problem, will post back here with findings.

          • Could you please email me with instructions on how to fix this problem? Greatly appreciated!

  5. Fantastic work, this makes my life so much easier!

  6. Hi Bradly,

    I can authorize Trello in Outlook and I could synchronize the activities but I can´t see on the calendar.


    • Bradly Sharpe

      Hi Carlo,

      I will email you to help troubleshoot the problem and post the results back here.


      • Thanks for the help, my problem was resolved.

        Fantastic work!!!

  7. This could be massively helpful!

    I’m struggling with Authorising Trello, are you able to advise Bradly?


    • Bradly Sharpe

      Authorise Trello is found under the File -> Trello menu item

  8. I have the link configured but I cannot see the cards on my calendar.

    • Bradly Sharpe

      Hi Tim,

      Have you got “Assigned to Me” selected? Most people that have this problem are not assigned to any cards on Trello meaning nothing is pulled from Trello. You could try unticking or assigning yourself to cards and see if that fixes your problem?

  9. I authorized, configured and synched my board, and unticked “assigned to me”…and can’t see any added tasks in my outlook calenar. Also, is there supposed to be a separate calendar only for Trello tasks? thank you!

  10. Regrettably I cannot use this tool conveniently at present. This is due to the fact my resolution is 1280×1024 and I am working with a lots of boards. The configuration page does not offer a scrollbar to move to the bottom of the page and to confirm settings.

    I found a way to configure it however. Waiting for the new release:-)

    • Bradly Sharpe

      Sorry! This was an oversight! At the time of writing this I didn’t have many boards within Trello, instead I had many lists.

      In the new version I am planning on having the board selections in a ListBox.

      I’d appreciate any other feedback/suggestions for the new version if you have more! As always, thanks for downloading/using!

  11. Is there any other way to authorise other than IE? Corporate policy won’t let me upgrade to a newer version, however, they let me upgrade to Chrome.

    • Bradly Sharpe

      Hi Philip,

      There is now a way to manually authorise the application in the latest version (v0.2.0.6)

  12. I’m finding this to be very useful and may be looking at deploying it in our organization. Is there a particular licensing cost for business use?

    Also one key piece of functionality we’re looking for is the ability to have flexibility setting reminders for due dates. Currently when the software syncs a card, the reminder is set for 15 minutes before. While I can change the reminder time, the next time the sync runs it changes it back. Is it possible to change the sync so that it preserves reminders set in Outlook?

    • Bradly Sharpe

      Hi Randy,

      There is no cost for any sort of use, this addon is free, however you could consider making a donation using the donation link above.
      I have just posted a new version that should not overwrite the reminder time and will also let you specify a default time (found in the configuration on the bottom right).

      Thanks for your support and feedback, if there are any other features/problems, please let me know!

  13. Hi nice to meet you, I just authorize Trello in Outlook but when i press Configure nothing happens, Tranks

    • Bradly Sharpe

      What version of the addon are you running? This should be fixed in the latest version :)

  14. I loaded version and it still is not holding the reminder time information. I am running Outlook 2013. The appointment keeps the color category information. I tried completely deleting and recreating the calendar, but that didn’t work either… Thoughts?

    Thanks for you help on this.

  15. Ok, I have installed it, but how do I get it to work? Sorry.

  16. Forget that last comment…figured it out…would love to be able to add card to Trello off of an email too! :-)

    • Bradly Sharpe

      I might try to add this in a future release! Thanks for your support! My main aim at the moment is trying to get an update of a calendar appointment to push to Trello.

  17. Hi.

    Could this add on run on Outlook 2017 ?

    “Trello Calendar” is create but i can’t find where i can setup to connect to trello account…


    • i made a mistake in previous comment : Outlook 2007 (and not Outlook 2017)

    • Bradly Sharpe

      I will create a document/walk through on how to configure this addon. In short, you need to go to the File Menu, authorise the addon, then go to the Calendar Tab and run the Configuration from the menu bar (far right has Trello Actions).

  18. I am lost :-( Is there a tuturial that I can follow? The download was successful and I have Outlook open but I don’t know what to do next… HELP

    • Bradly Sharpe

      I will create a document/walk through on how to configure this addon. In short, you need to go to the File Menu, authorise the addon, then go to the Calendar Tab and run the Configuration from the menu bar (far right has Trello Actions).

  19. Hi Bradly

    Many thanks for developing this add on. I have tried unsuccessfully to find a way to sync google calendar (can only sync every few hours) with Trello.

    I will make a donation for sure.

    I am not sure if this is a bug but probably you can advise me on an issue with this add on. If a card is archived and then deleted in Trello then the add on fails to delete the event in outlook calendar. Any thoughts?


    • Bradly Sharpe

      I will aim to fix this in a future release :) Thanks for your help!

  20. I’m having difficulty with your donation page. It will not accept my donation because I have a US address.

  21. Great work Bradly!!! Thank you for your after-hour work!

  22. Any chance this will be compatible with Macs?

    • Bradly Sharpe

      Sorry only for windows at the moment, I am thinking of making an iCal/isc subscription service that will pull all updates which can be added to any calendar, however not quite there yet :(

  23. Can you explain how you did this?

    •Create an Outlook Appointment item for each card using the data pulled from Trello
    •Update card if the appointment already exists
    •Push updates to Trello (Update card name, due date, description etc…)

    I was able to sync and add a Trello calendar in Outlook – but nothing has populated in it, so I know I am not doing something right?

    • Bradly Sharpe


      Are you having problems with this addon still?

  24. Thanks for putting this together! Any idea when it will be setup to “push” to Trello? Maybe it already does and I don’t know what I’m doing!

    • Bradly Sharpe

      Thanks Jared! Not really sure when this will be pushing to Trello, as this is a side project, I really have to spend more time on paying projects unfortunately.

      I have started rewriting this in C# which has the pushing code in it, still a few bugs/layout problems to fix before I can publish though.

  25. on the config menu I seem to be assigned to too many boards. I cannot scroll down to see all boards and I do not see the “ok” and “Cancel” button.

    • Bradly Sharpe

      Hi Oren,

      Sorry but that is a known problem in the current version. In the next update I’m replacing the list with something that will be scrollable. However since this is a side project, it has been put on the back burner for now until I have completed some paying projects.

      • Thanks. Good luck with your main projects

      • I also have too many boards to get to the OK button. Along with this is that your reading the Trello boards does not filter out closed boards (which I believe it should). Might take a look at your code and see if I can add a filter as well as a hotkey for the OK button and a scroll for the list. Any suggestions would be appreciated.

        • Bradly Sharpe

          Hi David, this is a known problem, I’ve fixed this in the next release, however there is a lot more work to do before it will be released. As it’s a side project with no funding, I’m not sure when I will get back to it.

  26. This is nice add on and was the missing lync for my project.

    • Bradly Sharpe

      Thanks for your comment and support Jason :)

  27. Hi, this is exactly what I was looking for and happy to donate but cannot get it to work.

    In Outlook I go to ‘options/addins’ and the Trello Outlook Addin is listed as ‘inactive’.

    When I click ‘manage COM addins’ at the bottom left, TOA is un-tiked in the list. I tick it and click ‘OK’ but nothing seems to happen.

    Any help appreciated.

    • Bradly Sharpe

      Hi JP, Have sent you an email to try and resolve the problem, will post back here with findings.

  28. Bradly:

    Thank you for this, it will be a great asset. What’s happening with me is I can configure once and it works but after that configuration is not saved. It always reverts to that first configuration. Thoughts?

    • Bradly Sharpe

      Hi Scott, I have sent you an email to try and resolve this problem, will post back here with findings.

  29. I’m running Windows 8.1 and Office 2013. When I ran the trello setup there was a message that a Visual Studio 2010 component had to be downloaded and installed, but then had an error that the download component could not be found, setup aborted.

    • Bradly Sharpe

      Hi Simon, do you know what the Visual Studio component was? I’m not using any external components that aren’t already packaged within the installer.

      • Hi – I’m not sure what happened yesterday, but today the install went ok.
        When I start the setup program, a dialog appears –
        Trello Outlook Addon requires the following items to be installed on your computer:
        Visual Studio 2010 Tools for Office Runtime

        I click on install, and it downloads and installs vstor_redist.exe. The rest of the install then ran to completion.

        I had to restart Outlook in order to see the new Trello Actions section, but when I’m prompted to Authorize Trello, what do I do next?

        • Hi – had to hunt around Outlook for a while, I see that you have to go to the File menu, click Trello, then authorize – I had to use manual authorization

          • Next question – Trello section appears on the Calendar, there’s a separate Trello Calendar, I clicked on Config and waited for a while, then click on Sync and get message:
            Please run the configration

      • Hi – it’s finally working. I think the problem I reported before re. Config and Sync might have been due to the firewall at work blocking it. At home without the firewall I was able to Config and Sync to Outlook easily.

        • This should be standard http/https requests for the trello data, correct? I’m asking because I’m also not seeing data after sync, but I dont *think* it would be firewall for me.


          • Bradly Sharpe

            Correct, standard http/https requests. Not sure why some people are having trouble when others aren’t.

  30. Hi,

    Does this work on Office365 – Office 2013 Professional (desktop version)?

    I installed it but it doesn’t appear on any tab.


    • Bradly Sharpe

      Sorry I haven’t tested this with Office 365.

      • Any update regarding Office 365? would be great to get it as I just moved to a Surface. Works on my work pc and its great!!

  31. Hi,

    Does this work on Office 365? (Office 2013 Professional desktop version).

    I installed it but doesn’t appear on any tab.


    • Bradly Sharpe

      Sorry I haven’t tested this with Office 365.

  32. I have been using your add-on for a week now, and I must commend you on a job well done. I look forward to the push functionality being implemented.

  33. In stalled you plug-in for Outlook 2007.

    I see a trello Calendar.

    I went to trust center>add-ins and trello is there says active

    I cannot find any configuration menu anywhere? What are the steps for Outlook 2007?

    • Bradly Sharpe

      The config menu should be in the menu when you view your calendars on the far right.

  34. Hey Bradly,

    I have installed latest released Trello Outlook Addon v0.2.0.6. But it is not showing trello calender in my outlook.

    Any suggestions?


  35. I can’t seem to get the thing to work, have downloaded the addon multiple times and the setup just always either fail or the program doesn’t seem installed . . . help . . . ? ?

  36. Ok, figured that one out, now the add-in keeps disabling itself or even doesn’t present itself as an available add-in . . .

    • It does not want to work on our laptops at work, runs perfectly on the desktop, but for some or other reason the laptops have a problem. Is there something I need to enable or disable for it to work?