This article will guide you through how to sync Synology Contacts with Microsoft Outlook, Mozilla Thunderbird, and CardDAV clients on iOS/Android mobile devices.

Before you start

Check port status

Make sure the following DSM ports required by Synology Contacts are open:

• HTTP: 5000
• HTTPS: 5001

Configure port forwarding to make Synology Contacts remotely accessible.¹

Find CardDAV URLs

1. Launch Synology Contacts.
2. Hover the cursor to the right-hand side of any contact or address book.
3. Click ⋮ > CardDAV.
   
4. Copy the URL for your CardDAV client.
   

Sync with Outlook (Windows)

You can use the free plug-in, Outlook CalDav Synchronizer, to sync your contacts.

1. With the plug-in installed, a new tab called CalDAV Synchronizer will be added to your Outlook. Click CalDAV Synchronizer > Synchronization Profiles.
2. Add a new profile and set the profile type to Generic CalDAV/CardDAV.
3. Select Contacts as the Outlook folder, paste the URL from Synology Contacts, and enter your credentials.²
   
4. Click OK to save the settings.

Sync with Thunderbird (Windows, macOS, and Linux)

You can use the free add-on, CardBook, to sync your contacts.

1. Launch CardBook in Thunderbird.
2. Right-click the left panel and then select New Address Book from the drop-down menu.
3. Select Remote and click Next.
4. Set the address book type to CardDAV, paste the URL from Synology Contacts, and enter your credentials.
   

Sync to iPhone

Hide address books

By default, your iPhone will sync all the contacts stored in Synology Contacts. If you do not want to sync certain address books, follow the steps below to hide it before the synchronization:³

1. Click your account in the upper-right corner.
2. Go to Settings > Address Book.
3. Untick the Display checkbox of the address book that you do not want to sync.
4. Save the settings.

Sync address books

1. On your iPhone, go to Settings > Contacts > Accounts > Add Account > Other > Add CardDAV Account.
2. Fill in the following information:
   • Server: Paste the copied URL.
   • User Name: Enter your Synology Contacts account.
   • Password: Enter your Synology Contacts password.
   • Description: By default, it will be the URL in the Server field. You can also enter any description as you like.
     
3. Tap Next.
4. Open iPhone Contacts.
5. If you cannot find the synced contacts on the list, tap Groups in the upper-left corner and tick your Synology Contacts account.
   

Sync to Android

You can use an application like DAVx⁵ (a paid app) to sync your contacts.

Synology does not guarantee the availability or the applicability of any third-party software and reserves the right to update or change the content of this article at any time without prior notice.

1. On your Android device, purchase and install DAVx⁵ from the Google Play Store.
2. Launch DAVx⁵ and follow their video tutorial to sync Synology Contacts.