If you use ActiveSync on your Android device you are not able to sync more than one calendar. The reason is the missing support in the ActiveSync implementation of Android.
Using Android multiple calendars is not a problem at all – as long as you use Google Calendars. However, in business environments – or if you want to keep your data private – it might happen that you want to use your own calendar server. In such cases the sync is most often done via ActiveSync – and there multiple calendars cannot be synced, see for example Google code issue #36797. Of course, there are also other protocols like CalDav, but unfortunately Android does not support these natively.
There are lot of discussions out there why this does not work, and the situation is not simplified by the fact that there are various ActiveSync implementations on server side and even on mobile side (Samsung ActiveSync vs Google ActiveSync, etc.). But for plain Android, the situation is clear: the code lacks the ability.
The Exchange ActiveSync protocol specifies types of folders – like one type for the default mailbox, one for user created mail folders, etc. And while Android does know the type “12, User-created Mail folder”, it does not know the type “13, User-created Calendar folder”. It does not know “14, User-created Contacts folder” either, by the way. It’s simply not implemented in the class “FolderSyncParser”. Just check the list in line 60-75, and compare it to the above given type numbers.
Thus you are not able to natively sync multiple calendars with plain Android and ActiveSync. If you really need it, you have to use one of the many, many hacks: export to Google calendars, create one user for each calendar on the server side, etc. – or use another protocol like CalDav which is not natively supported in Android but can be added by 3rd party tools.
I do hope that Google implements multi calendar sync via ActiveSync (or CalDav, speaking about) at some point in the future. I find the feature of multiple calendars extremely helpful in the daily office routine. But then again, there would be one reason less to use Google calendars on Android phones, so it might be that this is a political decision.
/home/liquidat 
Not directly related to your post but to ActiveSync. Is there a chance that we’ll get native support for ActiveSync (or Exchange) in KDE/Kontact/Akonadi?
PlaKen: there are plugins in development to sync Akonadi with Exchange via MAPI, which would the best way to do it technically. The one I knew was: http://websvn.kde.org/trunk/playground/pim/akonadi/exchange/ The best is you start there and try to figure out what the current state is.
I thought Google is about to remove ActiveSync support completely from Android?!
bruecke: Yes and no: Google stopped ActiveSync for their own services. You cannot sync Google Mail or Google Calendar with ActiveSync anymore in the future, you have to use CalDav, CardDav and IMAP.
That does not touch the ActiveSync-Client (!) support in Android, though.
Did anyone propose a patch to Android for this feature already ? It may not be very hard. (but I don’t know Java).
Aurélien, not sure, haven’t seen it so far. Also, it might be more of a political issue…
Yeah, but we can’t be sure of that until a patch has been rejected for no good reason. The political direction could be “we won’t spend developer time on that”, which would be understandable IMHO. Rejecting a valid patch is a different beast.
Well said… there is the google bug report I linked in the above post, I have never seen a patch submitted there…
While the above Google code issue #36797 was rejected, there was a new issue opend https://code.google.com/p/android/issues/detail?id=52270
I would like to know more about manufactory side implementations like Samsung ActiveSync. Will they work with multiple calendar folders? Where can I find more information about this?
At the moment, for us this is the reason for not using android phones in our company. We have to use iPhone or Windows instead. (WebOS also hat a good implementation of ActiveSync, but has been killed by HP)
Konrad, I think the best would be to ask Samsung or the corresponding manufacturer yourself. I only have one device with Samsung original software, and in that case only one calendar is synced.
Samsung knows nothing of this per level 2 tech support. Neither does Verizon Wireless. Only option is to switch to Motorola running Android since they do not use Active Sync or to use “Touchdown for Android” app.
Interestingly, I was able to synch multiple outlook calendars with my Droid X2. I’ve just bought the Samsung Galaxy S4 and discovered that I can’t do this very important (for me) synching. How frustrating! It might be a deal breaker for me. I spoke with Samsung tech support last night and they were useless. I don’t understand how it’s an Android issue when it can be done via Motorolla and not Samsung?! Argh. Does anyone have any thoughts about the new Droids out?
Again, Any phone with active sync will not support multiple calendars. Interestingly, active sync is originally a MS product. You need app “Touchdown” $20 at App Store after 30 day free trial. (I like it) or use Motorola . I gave back my new galaxy for the razr max hd
@patuniah: Not all Android mobile phones ship with the same ActiveSync implementatioin – the one of Motorola seems to support multiple calendars, while Cyanogenmod’s and Samsung’s implementation do not.
@Anonymous, that is simply not true: there are many phones which do support multiple calendars – it is just a question of the proper implementation. And please don’t use this comment section as ad place.