In order to get the best experience from WhatsApp, we recommend that you allow WhatsApp access to your phone's contacts. Here are a few things to know about using WhatsApp with your phone's contacts.
If you initially denied WhatsApp access to your phone's contacts, you can enable access by going to the BlackBerry 10 Permission Settings:
WhatsApp should automatically detect the contacts from your address book. To manually refresh your contacts:
If you have granted the app permission to use your contacts, but WhatsApp is still not detecting your contacts, or is displaying phone numbers without names, your contacts may be saved in a source that WhatsApp does not have access to. WhatsApp should be using the contact info (such as First name, Last name) from the contacts that are saved in the SIM, local, or Google/CardDav accounts on your phone. The easiest way to resolve this problem is to:
If your BlackBerry 10 device is configured with BES, you will likely have contacts from the "Work" profile, which WhatsApp is not able to access. Similar to contacts from social network accounts, please ensure that your contact details are saved to the SIM card, locally to your "Personal" profile, or to a CardDav account, such as a Google account. To give WhatsApp access to such contacts, please contact your BES admin.
If contacts in your address book don't synchronize properly with WhatsApp contacts, then possible reasons for this could be that:
You can learn more about how WhatsApp uses your phone's contacts from this FAQ article.