The best way will be to remove the duplicates from your online Exchange address book - with Outlook on your PC.
When I enabled my MobileMe account and selected Push access for contact information, all contacts available on my iPhone were erased and replaced with my MobileMe online address book. I was provided a warning that this would occur. I guess the same does not occur when enabling Push access for contact information with an Exchange account.
Does your problem involve an Exchange Account with Push access for contact information?
If not, are you syncing contact information with the Address Book on your Mac, or via Push with a MobileMe account?
If you are syncing contact information with the Address Book on your Mac and there are no duplicates in the Address Book, under the Info tab for your iPhone sync preferences below Advanced, select Contacts under Replace Information on this iPhone. Select Apply and then sync.
I am syncing with Exchange and getting duplicate, triplicate, + entries.
When i turn of exchange syncing, all my contacts are gone. Turn it back on and the entries return in duplicate, triplicates ++ Have turned off contact syncing on MobileMe on all devices, reset and still get duplicates all indicating the data duplication is files on the server.
Entourage 2008 shows no duplicates on the server however... using Outlook 97 via parallels shows multiple duplications! Am trying to organize and delete duplicates via Outlook 97. However the older contacts I delete from Outlook 97 do not appear in Entourage. augh.
Used Outlook 97 via Parallels to regain contacts in proper fashion. Still would not show in Entourage until I selected all, and modified slightly (I put all my contacts in a category). This "refreshed" all the contacts and they appear consistently in Entourage, Outlook 97 and on the iPhone.
Continuing to keep syncing with entourage & mobileme off for a while. Enough time spent on this.
I have the same issue as well. 2 exact copies of each contact. (no triples)
I synced my new iPhone on my Mac Mini last night... the contacts were several months old (an export from Outlook). It looks like it didn't drop the existing contacts(as the dialog suggests) when adding exchange... rather it merged them.
Testing an edit... I changed the Home# on Carl's first Listing on the iPhone. It updates exchange immediately. Changes to his 2nd don't show up in outlook. Changes in outlook take much longer to reach the iPhone... but always update the first listing.
Deleting the 2nd listing on the iPhone seems to solve the problem. Deleting the first listing deletes it on exchange. Editing the 2nd listing doesn't do anything (that I can tell) to exchange.
As best as I can tell, the 1st instance of the contact is the Exchange contact... the 2nd instance is the original contact you created on the iPhone or imported.
iPhone 3g 2.0.1 (syncing with mac mini at home)
Vista SP1 (not syncing with PC yet)
One of the issues that the iPhone has is with catagories in contacts. I have over a thousand contacts, each in multiple catagoies; Christmas mailings, company 1, company 2, family, food, etc. Some contacts are in multiple catagories so when the iPhone syncs my contacts is does not know how to sort the catagoies and thus I have duplicates, triplicates, etc. This is a limitation of the iPhone... This is just one of the many things that makes me wonder if the iPhone is really up to the task of my old stinky Samsung i760 or even my old Q for that mater... Sure it's shines, well fluffy to be honest but it's not business ready yet. Maybe in the next revision
iphone 3g exchange active sync contacts catagories duplicates
Ok... I win the dumb-*** award!
The reason for my multiple contacts: I had a backup of my old phone in another contact folder in my exchange mailbox. Removed it... problem solved for me at least.
However, I've been checking it out and it supports lots of options that ActiveSync never seemed to care about. Multiple Contacts folders... you can select a specific folder when looking at the Contacts by going to Groups. IT shows all your Contacts folders, and lists your Active Directory Global Address List as a "Directory" (though doesn't look like it syncs this list, rather it searches as you type)
So far I like using exchange... though it seems to have a little trouble opening the Contact list... it takes a few seconds each time when you open it up (though I have 140 contacts... plus only 10 or so in exchange).
I was having this problem too except every contact was a duplicate only on my iPhone. I was looking around in both entourage and exchange and wasn't able to find anything that jumped out at me (like the post earlier about the back up on the server). I did notice that my contacts on the server were not duplicates. I disabled the contact push on my iPhone and then about 10 mins later I re enabled the push and that took care of it. I think part of the problem was because I just upgraded to the 3G from the original, but I hope this helps someone.
I have and iPhone 3G i configured for my boss and the sync worked fine. No duplicates at all. That was a week ago. Over the weekend something happen to cause duplication of the contacts on both the phone and in outlook. Also the phone reset and lost connection to the mail server. I reconfigured the phone and sync, when it was time to sync the calendar it told me it would delete whats currently on the phone and bring in contacts from exchange. I clicked OK but now i have duplicates in outlook and on the phone. I'm not sure what caused the duplication to begin with but what is a good way to fix this? Is a manual delete in outlook the only way?
Joevpt you are a champ! Removing cached exchange mode did it for me. Three additional steps I had to use to remove the duplicates: 1) go to each contact group in Outlook and manually remove the offline contact information (right click on the group and choose Properties. At the bottom of the General tab, click Clear Offline Items); 2) Exit out of Outlook; 3) Re-sync (I'm syncing via MobileMe) and replace your Outlook data with the data from MobileMe. When I restarted Outlook, I had only one set of contacts.
Information on how to remove cached exchange mode can be found here: http://kb.iu.edu/data/amxk.html