Troubleshooting Contact Sync Issues and Effective Cleanup Solutions

In the realm of digital synchronization, individuals are generally divided into two groups: those who effortlessly manage iCloud sync and those who use iCloud sync. Admittedly, this might be a slight overstatement, but my personal experiences with iCloud sync date back to the MobileMe days and are fraught with numerous issues.

Most issues stem from syncing contact data. Occasionally, iCloud will inexplicably fail to sync, and I usually discover this when a device lacks updated or new information that was entered on another device.

Over the years, I’ve developed a method I call “The Nuclear Option” for resolving issues with my contact database.

This involves backing up contacts from all devices and the iCloud web client, followed by a complete purge and re-importation of the data, ensuring all duplicates are removed. While I can’t promise universal success, this method has proven effective for me.

When backing up, I prefer using the vCard format over Apple’s native format to avoid any iCloud-specific metadata. To export your contacts as a vCard, select all contacts in either the Contacts app or, then choose File » Export » Export vCard….

This format is highly portable and can be used across various platforms.

It’s important to note that exporting in vCard format does not preserve group information. If maintaining groups is crucial, opt for “Contacts Archive…” instead.

Here’s my step-by-step guide for the process:

  1. Export contacts from each device and

  2. Verify each export, using QuickLook to check the number of contacts in each vCard.

  3. Securely store all exported contacts.

  4. Delete all contacts from after verification.

  5. Ensure each device has zero contacts post-sync.

  6. Disconnect your network connections on your iMac.

  7. Re-import all contact data collected in step 1.

  8. Use Contacts Cleaner to resolve any issues.

  9. Back up the cleaned data for safekeeping.

  10. Inspect all contacts for any remaining issues.

  11. Export a final vCard and store it securely.

  12. Reconnect your iMac to the network and sync everything back to iCloud and your devices.

While generally effective, this method does have its limitations. For instance, Contacts Cleaner sometimes struggles with SMS short codes and some international numbers.


Jacob is a dedicated writer for TUAW, bringing readers the latest and most insightful news about Apple products. With a keen eye for detail and a deep understanding of the tech world, Jacob covers everything from the newest iPhone releases to the latest updates on macOS. His articles are known for their clarity and depth, making complex topics accessible to all. Whether it’s the Apple Watch, iPad, or MacBook, Jacob’s expertise ensures that TUAW readers are always well-informed.