It's easy to delete contacts from your iPhone and there are several ways to do it. This article describes the best way to delete a single contact, multiple contacts, or all your contacts.
This may be the time to do some housework or no longer need contacts. Anyway, here's how to remove contacts from your iPhone.
Delete a single contact
Go to Contacts and tap the contact you want to delete.
Tap Edit> Delete contact.
Confirm that you want to delete the contact by pressing "Delete contact".
Delete all contacts from one source
IPhones can extract contacts from email accounts such as Gmail, Outlook or Yahoo Mail. Overall, it really makes it easy to add and delete contacts on your iPhone. If you delete a contact from a linked account or from your iPhone (as described above), it will be deleted in both places. To delete all contacts from a single source, you can delete the entire account or simply disable synchronization of contacts from that source.
To see which sources are linked, go to Settings> Passwords and Accounts.
Accounts that sync contacts will have the word "Contacts" underneath.
Tap the account from which you want to purge contacts. From there, you can turn off contact synchronization by tapping the "Contacts" switch and selecting "Remove from my iPhone".
You can also delete the entire account (mail, contacts, calendars and notes) by tapping Delete Account> Remove from My iPhone.
Delete some contacts, but not all
It is there that things get complicated. There is no way to delete multiple contacts on an iPhone (unless you delete them all): it's all or nothing. However, not everything is lost. You can delete these contacts from the source account and these changes will be synchronized with your iPhone. Depending on the location of your contacts, there are different ways to delete multiple contacts. Check your vendor's documentation (for example, Gmail, Perspective, Yahoo mail).
But now, you're wondering if these are contacts that I have saved in my iPhone and not in an account. Well, you're lucky because there is a workaround for that. Go to icloud.com and log in with your iCloud credentials.
Click on "Contacts".
Select the contact you want to delete by pressing Ctrl + click on it.
Press the Delete key on your keyboard, and then click "Delete" in the dialog box that appears.
Once done, the changes will be synchronized with your iPhone.