OnePlus
Delete a Contact auf OnePlus
Contacts on a OnePlus phone are managed through the Contacts app, and deleting one removes all associated data in a single action. This includes phone numbers, email addresses, physical addresses, website links, and birthday entries stored on that contact card.
If the contact is saved to your Google Account, the deletion syncs automatically once your phone connects to the internet. The entry disappears from every other device signed into that same account, not just from the OnePlus phone.
To remove a contact, follow this path:
Open the Contacts app ➔ Tap and hold a contact ➔ Choose more contacts if desired ➔ Tap on Delete ➔ Confirm with Delete
Holding down a contact lets you select additional entries before deleting, which is useful when clearing out several old numbers at once. The final confirmation step exists because the action cannot be undone from within the app.
If you only want to hide a contact from certain apps or remove it from one account while keeping it in another, deleting is not the right move. In that case, edit the contact and remove the specific account link instead, or check which account the entry is stored under before deleting it entirely.

