If you have contacts in your Google account and would like to centralize them across all your accounts, you can do so via Google Backup Contacts. This method is robust as compared to other address book apps as it allows you to enter contacts information in a detailed manner. This is inclusive of your contact’s birthday dates. But is it necessary for you to backup your Google contacts?

Like all other programs, Google Contacts does not have immunity against data loss. Even as you make good use of its other amazing features, you should look out for weak spots that might lead to loss of data.

Google Backup Contacts - Why You Should Backup Your Google Contacts

• Import contacts: If you have contacts that are scattered in different devices like in your phone, others on your PC while you have written others in a notebook, it is a good idea to have them all in one place. Google Contacts provide the best platform for this. However, there is possibility of experiencing a sync error as you import your contacts. This might lead to loss of some contacts and you may end up with fewer contacts than you had in the first place. That is why you need a backup option.
• Groups re-assigning: If you have group contacts and would like to move some contacts to another group you can easily do so. However, you may decide to delete the contact from the first group and this might actually delete the contact completely. If you had not backed up that contact elsewhere, you may end up with some trouble.
• Contacts merging: If you have just realized that most of your contacts have multiple entries, chances are that you want to clear them up. That way, you will be left with one version of each contact. Merging is mostly the solution but it is somewhat tricky and does not always pan out as planned. You may remove duplicates and later find out that you only have very few contacts. If you had backup, you would have just deleted all contacts and retrieved them from your backup.
• Deleting by accident: The ubiquitous data loss scourge is man’s error. It is actually easy to select a contact then delete it only to realize that you did not want to delete it. This happens more often when your mind is preoccupied or you are in a rush. So what do you do? Go for the contacts you had backed up.