Sync Contacts Across Google Contacts, iCloud, and Office 365 / Exchange / Outlook Accounts
How can I sync multiple accounts together?
In the past, if you wanted to keep identical address books in two (or more) different Google, iCloud or Exchange accounts, the process was tedious and risky. You’d have to export your contacts from one, import them into another and hope that nothing got lost in the process. Then, as soon as a change happened in either account, you were out of sync once again.
With Contacts+, keeping your contacts in sync across multiple Google accounts is simple. Just go Contacts+ for Web, click Sync Sources -> Add sync Source -> choose up to 5 accounts that can be synced together.
You can have identical address books across as many as five Google accounts (with a Premium subscription)
How can I adjust my sync settings?
Once you have your accounts loaded, you can choose how you want your connected accounts to behave. In order to create identical contact listings across your multiple accounts, you’ll want to turn syncing ON for all of your connected Google accounts.
With that, you're all set. No exporting, importing, or continual updating when something changes. Contacts+ is going to handle all of that tedious work for you. When a change happens to a contact in one address book, it will automatically sync to your other address book via the power of Contacts+'s syncing abilities.