Not all contacts were deleted, one or more of the contacts may be read-only

Unlike some Android devices, contacts are neither stored locally on an iPhone nor in SIM. They are synced to an email account that you had Google, iCloud, AOL, Exchange, Outlook, Yahoo or any Other

If Contacts on iCloud, try this --> Restore contacts, calendars, bookmarks, and more using ...

Else Add the email account that stores your contacts in the IOS mail app and enable Contacts.If you have a corporate email account added through a profile on your device, please check with your organisation's system administrator.

When you want to delete the contact, you need to follow this step:

go to Contact-Edit-Delete the number manually-Done.

and then go to Whatsapp (in case you still have the chat history), Delete chat. And go back to contact-Edit-Delete contact.

That’s it.

I’m getting the same message but can’t use the business account it was associated with because it’s been deleted and I no longer have access to it. It was an Exchange account that I can’t get into.

The number is prob saved on a app like WhatsApp.. if you delete it from there it should go from your contacts aswell

Thanks ..It works

Just delete every information saved in that contact: the number, mail id, birthday…everything even the photo.

then the new edited contact will be saved as ‘No name’.

Now delete it!😎