How to Clear the Outlook Email Address Autocomplete Cache


How to clear the Outlook autocomplete cache in Outlook 2010, Outlook 2007 and Outlook 2003 and remove old email addresses from your nk2 file.

Microsoft Outlook 2003, Outlook 2007, and Outlook 2010 have a feature called Email Address AutoComplete which many of us take for granted every day. As you type an email address into the TO: CC: or BCC field, Outlook will display a list of matching email addresses from the Outlook AutoComplete cache (IE: Email addresses you have already used.)

Clear Outlook Autocomplete Caches

Here’s an example:

outlook auto complete

As convenient as the AutoComplete feature is, there are times when you need to remove these cached email addresses from the cache. For example, perhaps someone at work just lost his/her job, and the email address is no longer valid. Or maybe you made a typo while sending an email and now that address is stuck in your cache. The good news is getting rid of that address from your auto-c cache is simple no matter the version of Outlook (2003, 2007, or 2010.) Just follow the steps below.

Solution: The fix is easy:

  1. Inside Outlook, type the email address you wish to clear from the cache until Outlook displays it as shown above.
  2. Press the down arrow key to select the email address and hit the delete button.
  3. All Done.  That entry should now be gone from the Outlook Auto Complete cache.

Solution #2 (Nuclear Bomb): This is another option if you want to delete all addresses in the cache file (outlook.nk2).  Note, Solution #2 is for Outlook 2003 and 2007 only.  Read this post to clear the AutoComplete in 2010.

  1. Close Outlook
  2. Open Windows Explorer or IE and Paste %APPDATA%\Microsoft\Outlook into the address bar.
  3. Delete the Outlook.nk2 file in this folder
  4. All Done

clear file

Solution #2 is comparable to the “Nuclear Bomb” being that it will delete all your cached email addresses.  It should only be used if you want to wipe the file clean or if you have corruption issues with your .nk2 file.  Once you delete the .nk2 file, then the next time you open Outlook it will automatically create a new .nk2 cache file, and Outlook will once again begin caching the email addresses you use.

But what if all you want to do is disable the Outlook Auto Complete entirely? Easy. I wrote about disabling the Autocomplete for Outlook 2010 and Outlook 2003 and 2007 earlier. Take a look there, and you should be good to go!



  1. DJ

    Exactly what I was looking for. Found the outlook.nk2 and blew it away! Thanks for getting this out!

    • c lowwe

      Thank you very much this is exactly what I was looking for!

    • MiK

      I am using Windows 7 and outlook 2007, but .nk2 file does not exist what can i do for that? even i have checked on outlook 2010.

      • HQ

        I have that problem too–no .nk2 file in the folder. What I did instead:
        1) Open a new email
        2) In the address field, type “a”
        3) Hit the down arrow and press and hold “delete” until all the auto-complete names disappear
        4) Delete the “a” in the address field, and type “b”
        5) Repeat steps 3-4 for all letters of the alphabet and numbers 0-9.

        This clears everything out so you can start fresh :)

        • HQ

          *To clarify step 1): Open a new email in Outlook

        • Praveen

          Thanks dud It works fine..

  2. POneil

    Love the post. Another great writeup.

  3. MrGroove

    Welcome DJ & POneil!

    Glad to see the article helped you out.

  4. Dan

    We did a migration of email from one domain to another. Everything pretty much has came across flawlessly. One minor issue we have is people aren’t able to display their contacts through the address book. I look at the contacts properties and the click on the permissions tab and the place to check to use this floder as an address book is grayed out. How do I activate this box? The user has permission on their computer and their email to make changes but for some reason this box is grayed out for several users.

    Thanks for your help.

  5. Prashanth DN

    Autocomplete option is enabled in my outlook but the cache gets cleared once almost every month. How can I stop this?
    – Prashanth DN Kannadiga

  6. MrGroove

    That’s very odd. First we need to figure out if it’s being deleted or corrupted….
    Look in the folder: %APPDATA%\Microsoft\Outlook\outlook.nk2 and find the file date of the outlook.nk2 file. What is it?

    Also, it might be easier Prashanth to move this conversation into the . Keeps from getting the comment system here to cluttered.

  7. DW

    Does anyone know how to stop auto complete regenerating its new .NK2 file once you’ve cleared it?
    I want to turn the function off all together… I know this can be done in previous versions of Outlook, but not 2003.

  8. MrGroove

    Welcome to the site DW.

    The process is simple, in fact I’ve already written a how-to on disabling the auto complete feature for outlook 2003 and 2007. Here’s the URL:

  9. Renee

    I seriously wanted this single delete from cache to work. I tried it so many times I’m crazy. I begin typing the name. I arrow down to it in the list. I hit delete. It goes away from the list. The next time I start to type the name, again, it comes back. Here’s the deal. I built an e-mail box with someone’s name and then changed the ‘resolve’ name, later. The address is the same, the resolve name is not. That’s what I’m trying to deal with. Ideas?

  10. MrGroove

    @ Renee: I’m not sure I understand your question fully but it might have something to do with caching in your GAL or how the account is setup in Active Directory.

    If you want to continue troubleshooting the problem, please create a thread here: This comment system is not a great “forum” for troubleshooting issues.

  11. SigEp

    Thank you… You are da man!

  12. MrGroove

    @ SigEp
    Thanks and Welcome to the site!

  13. Chad R. Smith

    This answered my question, and worked right away! Nice post!

    I can’t believe that (Expert Sex Change) charges for someone to read how to do this! I think your post should be #1 in the search. Those guys are a joke. Just my opinion on that, well said and helped me out a lot! Maybe I will stop sending e-mails going to my new boss to my old one. My fault for not finding one named differently.

    Take care,
    Chad R. Smith
    President of Get A Supplier INC

  14. Elizabeth Crisby

    How about clearing cache for Outlook 2000 is it the same

  15. lashonda franks

    How do you enable the cache. It was there, but now no names pop up when a letter is pressed. the nk2 files is not deleted because I see it under the profile name and the option is enable in outlook email options. Please help!

  16. RUGBYBOY14

    Phew, needed to hide address from my wife for a suprise, without this i would be in trouble

  17. MrGroove

    @RugbyBoy14 – Welcome to the site!
    Excellent! I’m glad it helped you out! BTW – If there’s ever something you can’t figure out, feel free to post in the Forum!

  18. Danger Dave

    I have Office 2007. There are three files titled Outlook but they are an SMS, XML, and a Outlook Data File. Are any of these the ones I am looking for? If not, how would I go about clearing the cache for the 2007 version?

  19. MrGroove

    @Danger Dave,
    First, Welcome to the site Dave. Second, the article is actually written using my Outlook 2007 client. With that said, if you do a search on your hard drive for outlook.nk2 you should find all instances of the outlook cache file. If you delete the files you find you should be good to go.

  20. pilar

    Thanks a lot!! I have been trying to delete obsolete names without positive results. Now, I know how to do it!!!

  21. jffga

    GOD bless you!

  22. MrGroove

    @Pilar & Jffga – Welcome to the site and thank you for your comments! I’m glad the article was beneficial!

  23. Raj

    Superb! was looking for a fix for ages :)

  24. MrGroove

    @Raj – Excellent! Thanks for the comment!

  25. Jade

    groovy man! love the post.

  26. Groove River

    This method helped me a lot.


  27. Bruce

    Re removing pesky names that show up (and are incorrect) in auto complete


    Tried both options above. No can do.

    The extenstions that show up in option 2 are:
    .dat and .srs no .nk2


  28. Bruce

    I got the auto complete to cease after some playing .

    Thanks Groovy


  29. Prashant

    thanks. i was able to save my email entries. great help

  30. Mike

    BEEN LOOKGIN FOR THIS for like 2 months!!!!

    Thanks, you are a life saver my friend and you rock!

  31. Mike

    Is there a way to copy all the emails in your cache. I’m leaving my current job, and want to keep a list of all the contacts I’ve made over the years, but I don’t have them all in my address book. Is this possible. Just want a list, not a file, to transfer over to my personal computer.

  32. MrGroove

    You have a few options. What ever you do, be sure to grab a copy of your .nk2 file. You can find the location in the Tutorial above.
    My recommendation would be to grab a copy of NK2View from

    At the time of this writing, the latest version of NK2View is 1.20. After you download the software, just run it from any folder and it should find your NK2 file. You have a few options to either Save the list of emails into a TEXT file or copy them into your address book. You can also point the app at another Outlook .NK2 file and convert it as you like.

    Hope this help!

  33. MrGroove

    @Bruce – Glad to hear you figured it out. Let me know if you have any other questions!

  34. Robert

    Having deleted Outlook.nk2, how do I put it back should I want to?

  35. MrGroove

    @Robert – Hi Robert, if you deleted the .nk2 file, it’s pretty much gone unless you saved a copy of it. Did you save it somewhere? Also, what OS are your running? Vista or XP?

  36. Gabriel Lima

    I am with a problem… how i can send a e-mail for everyone on this cache ? or how i save then to my contacts list ? If you can, please mail me !

    • MrGroove

      You will need to use an app like this one: which has the feature to export them. Give that a shot.

      • Gabriel Lima

        Its exactly that what i need. Thanks for the help, now i can help others !!! ^^

        • MrGroove

          Awesome! Glad that worked out. It’s also scriptable so that makes things easy if you need to do clear or modify the .nk2 file in bulk using batch files.

  37. Marti Scott

    Your posting on how to get rid of of the typos in the cache was PERFECT and right on. Now I can quit sending email to someone intended for others when I am in a hurry.


    • MrGroove

      Awesome! I’m glad my blog post helped ya out! Thanks for the feedback.

      • Brett C

        Seems like you have lots of cool ideas, I need to remove my cache email system form Outlook but I work on an IMAC so I use entourage.

        I keep sending emails to people I don’t want to because of this and it is very frustrating.

        Any ideas?

  38. Ray

    I have outlook 2010 and automatic name checking and use auto complete are checked, however it won’t auto populate the “TO” field when typing an email address. Any thoughts?
    Thank you,

    • MrGroove

      @Ray – Yeah this seems to be happening to a few ppl out there. Are you using IMAP or Exchange or Google Apps as your email server? Also, you might have something corrupt. You should try to use this Tutorial to clear everything out and start working again.

      • Ray

        POP3 Exchange server. Cleared it yesterday but still won’t populate “TO” when typing email address.

        • MrGroove

          According to Microsoft –

          The Recipient AutoComplete list is now stored on the Exchange Server. A user’s recipient AutoComplete list is now available to any computer on which Outlook 2010 runs that is connected to the same Exchange account.

          However, if your using Outlook via POP3 or IMAP and not with Exchange, then it will be stored in your PST file. I’m thinking perhaps your using an older style PST file (ANSI) and not the new PST file (UNICODE). My suggestion would be to create a new PST file, sync your mail and try again. Here’s more info on that:

          This is really interesting so if you could test out this theory, that would be great. That being said, if you created this PST file when you installed Outlook 2010, it will be Unicode so…. might not be much more to try then…

  39. vipul

    that’s good aqnswer i am very happy beacuse my problem resolve

  40. Neal

    <3 <3 <3

  41. bduncan

    thank you, if I send another email to the wrong Melissa again I will kick myself in the arse.

  42. Charles

    I have lost the auto complete function but the selection is still showing in the adavanced email options as selected. I am running outlook 2007. Any thoughts?

  43. soni

    thank you for the info, it worked

  44. M

    Thank you — this was so much easier than the MSFT suggested fix and worked perfectly.

  45. Kris

    Thanks so much for a very useful bit of information. Clear, clean, and simple. I’ve lived with several “wrong” addresses in the cashe for far far too long.

  46. Nicole

    I second Kris’s thoughts. Straight and to the point, your explanation was exactly what I needed. Thank you so much for making this an easy fix!

  47. shahid khan

    Please can you help me on this matter?
    My problem is simply that, for a certain user (who of course happens to be the executive director), Outlook 2010 no longer retains address autocomplete information. It used to work but doesn’t anymore. And naturally, he really likes this feature and I look really stupid for not being able to get it working for him again.
    I understand that Outlook 2010 no longer uses .nk2 files, but rather stores the data in some hidden ?

  48. shahid khan

    Please can you help me on this matter?

    i just want to know how to recover my addresses in address bar i just make offline address book after all disappear addresses in the address bar ,

    how i use same like before
    waiting your reply

  49. Deric

    This was easy to find and use.

    Great job

    Thank you


  50. Marco

    Thank-you for the information. Some information is never too old.

    • Steve Krause

      True :) That was an oldie but still very new for many. Welcome to my blog.

  51. Bailey Dunmire

    THANK YOU THANK YOU! So easy yet so far from my reach!

  52. Stevie

    Cheers, really useful tips, well laid out and easy to follow

  53. how to build a website

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  54. Sue

    I want to import the emails in the cache file, many of them I never added to contacts and would like to do that now.

    Is there a way to add them in bulk?


  55. denver

    You can also clear it by using this command in the Run box:

    Outlook.exe /CleanAutoCompleteCache and click (as per picture below)

    Found here:

  56. Raj

    Thanks use full suggestion.

  57. Vikram

    Hey thanks
    Your solution worked

  58. GoatSoapLady

    Such a simple fix – thanks Steve! I always over-analyze & over-complicate everything – overlooking the most obvious. Just signed up for your newsletter – thanks for everything your doing Steve!

    • Steve Krause

      @492253d8c9bd27e04d198ba3979dd85a:disqus You are very welcome! Welcome to my blog. You can say thanks by spreading the word :)

  59. Vaults350

    Brilliant solution – thanks

  60. Marcus


    thanks for the article. I have a curious problem. While I knew about the caching behaviour as described by you, I have the following problem at one of my installs.

    I have deleted one certain address from the suggestions list because Outlook seems to have that address wrong. The respective address is not part of any contact information and after I deleted it it doesn’t pop up when typing the address.

    But as soon as I leave the To-field the address gets converted to the old, damaged address which should have been deleted. Any ideas, why this happens?

    Thanks a lot!

    • Andy

      Wow. I am not the only one. I can’t send my biggest client an e-mail address from outlook because of this. I put in his new e-mail address in his contact file, and as soon as I tab through, the old one pops in there. The old address is somehow linked to the new one. I have deleted and reentered the contact, and it still does the same thing.

      Hope we get an answer.

  61. Muthu

    Thanks! It worked well!

  62. Utility Industry

    outlook.nk2…. many thanks, our IT department rebuilt my outlook after a crash and me recovering this file has saved me a lot of time!

  63. VIP

    My company has two email id and i want both to run in the same outlook, need help urgently.

  64. Joe

    I read through the responses and did not see my exact situation. I want autocomplete to be on for email addresses but I only want it to use my contact list as the source. I do not want to use the cache at all. Is there a way to do that ?

  65. Larry Jenkins

    No matter what I have tried I cannot get adresses in auto fill to delete, highlighting and delete button does not work for me, I have several address that are obsolete or incorrect and I want to remove them from autofill, they have been removed from the contacts list successfully. what can I do???

    • Gregg Looker

      I’ve been working on this problem for a week now and when I went with my gut instinct rather than any of these suggestions, I found the solution and it is absurdly easy.
      The problem was the auto-complete history came over from a Windows Outlook 2010 to a Mac Outlook 2011. When you type the first letter in the “To” field, up pops all the cache entries that begin with that character (right or wrong). Some of them have “x”s (which can be deleted just by clicking on the X. But some say “other” and cannot be deleted.
      Further research showed that these addresses were all coming from a “Contacts Search” button, then “All folders” and then selecting “Suggested Contacts”. When you open that folder, the individual card entries have no “delete” option. So how to delete them?
      The solution was to open “Address Book” from the Mac OS system tray, and then editing the Address Book (which holds ever entry ever typed into a “to” field. Wella, no more “other entries” that can’t be completed and no longer auto-complete bad ones.

  66. Matt

    I am going to give this a shot, but it is a bit different. I have an employee that when she hits the reply button it autopopulates a different email address. I went into the suggested contacts and removed that account, but it still shows up when replying. Will update if this fixes that problem as well.

    • Matt

      Yeah this didn’t work, still has the reply to person as the wrong one. Will keep searching.

      • Gregg Looker

        Read my id10t solution above.

  67. Barbara Kelly

    Thank you for your easy solution to this — has been bugging me for a few months now since I was the one who made the typo in a name. :)

    • Steve Krause

      @be719b3c6902575a9ed672ac9c099ba4:disqus Yeah the Typo is a big reason to use this trick. Also when people leave the company and you won’t be sending them email any longer. I’m glad my blog helped ya out.

      Welcome to groovyPost!

  68. richard loudon

    tried to delete on imac. fn + backspace does not seem to work. confused!

  69. San

    Thanks a lot! solution 1 was great!

    • Steve Krause

      Awesome. Glad this old tip helped ya out!

  70. michgns

    Does this work for google chrome email too?

  71. S

    thanks so much for this quick and easy fix.

    • Steve Krause

      You bet! Glad we could help. Welcome to gP.

  72. robaldred

    Finally a solution,#1 works perfectly for removing rogue entries

    • Steve Krause

      Yeah — that’s an old one but it still works perfectly, even with the new versions like Outlook 2013.

      Thnx for the comment!

  73. Camille Ortiz

    I’ve sent so many emails to the wrong guy because his name always comes up first and it was so annoying! He’s going to be glad that I’m not emailing him by mistake anymore. Thanks!!!

    • Steve Krause

      awesome! And this tip works for outlook 2013 also so FYI there.

  74. cynthia

    I tried the arrow and delete way and it did not work..any additional help will be much appreciate,

  75. Jarrod Spencer

    Thanks…worked perfectly on my 2007 edition!!!

    Now if you could tell me why my contacts do not show up when I want to just click and add them to an e-mail. None show up…

    • Steve Krause

      Say that again. So your contacts are not showing up in the auto-complete?

  76. Jane

    was reading your older post on how to clear email addresses. We have Microsoft Office Outlook Web Access and we have been having a time with our system keeping old email addresses that either had been deleted from our system or we had updated.

    I found your post on how to delete a auto completed email- This worked.

    Solution: The fix is easy:

    Inside Outlook, Type the email address you wish to clear from the cache until outlook displays it as shown above.
    Press the down arrow key to select the email address and press the delete button.
    All Done. That entry should now be gone from the Outlook Auto-complete cache.
    Now I tried this, but maybe because our version is “office”, I did not see a file named “outlook.nk2.

    Solution #2 (Nuclear Bomb) : Another option if you want to delete all addresses in the cache file (outlook.nk2). Note, Solution #2 is for Outlook 2003 and 2007 only.

    The other issue I have is I created a “distribution list” and named this list, and when I go to create an email, and beginning typing the name of this list, my system is not picking this name up at all?

    So I would like to maybe clear out the complete autocomplete file if possible and figure out why my system is not picking up the name in my contact list now?

    Many thanks for any help you can provide.

  77. Bruce

    This has been bugging me quite a while. Glad to find solution. THANKS!

  78. Alan

    I have tried this three times, without any success. the entry goes from the address bar, but still comes up again, on a prompt of the first 2 letters of the name.

  79. Steve

    I am running Outlook for Mac 2011. I want to delete certain email addresses from my auto correct file when I type a name into the ‘to’ space in an outgoing email. I scroll to the address I wish to delete and press the delete key. Addresses move but none are deleted. What do I need to do to delete and unwanted auto correct email address? Thanks.s

  80. Matt

    Exactly what I was looking for, thanks!

  81. SK

    This is what I was looking for. Thanks

  82. David

    I’m still having problems deleting old names. I’m operating Firefox on an old Windows XP with Microsoft Office Outlook 2003.

    I can highlight and delete names but as soon as I turn the computer off and then back on again they reappear. I can’t seem to find the Outlook.nk2 file either?

  83. takir

    exactly what i want. thank you

  84. WK


    There are some similar situations described above, but none of those solutions applied.

    I have a client whose contact was originally entered by what must have been a functional illiterate. Whenever I “reply” to the client, the misspelled address populates. I have corrected the contact and entered a correct spelling, but this dinosaur keeps popping up when I reply.

    The bad address does not show up when typing the first few letters in the “To:” field. The correct one does. The bad address appears in format ” ‘Name’ .” The good one is in standard format.

    Where else can I go to purge this vexation?

    Windows 7 Enterprise, OL 2010

  85. tanveer

    Exactly what i was looking for well done

  86. JP

    This will still be relevant for years to come!

  87. Paul

    Thank you! I was looking for it for ages and it’s easy as that!

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