"If you allow partial access, you'll be prompted to manually select which of your phone’s contacts you want WhatsApp to have access to. In this case, some contact names may not appear when you try to call or message them on WhatsApp. If you create a new contact in your phone’s address book with limited access, it won’t show on WhatsApp until you grant access for this contact in your settings. You can change access at any time by going to your phone's Settings > WhatsApp > Contacts."
https://faq.whatsapp.com/1173713140597106/?cms_platform=ipho...