how to delete contacts in bulk not one at a time

Hi helgacollins,

Thanks for posting in Apple Support Communities.

We understand you want to delete contacts from your iPhone quickly. If you have contacts in iCloud, you can select multiple contacts at once to delete.

Delete contacts on iCloud.com

You can delete a contact in Contacts on iCloud.com. When you delete a contact, it’s deleted on every device that has Contacts turned on in iCloud settings.

1. In Contacts on iCloud.com, click the All Contacts group in the sidebar, then select one or more contacts you want to delete.

2. Press the Delete key, then click Delete.

You can find these details in Delete contacts on iCloud.com - Apple Support.

If all the contacts you want to delete are synced from the same account, go to Settings > Mail > Accounts and choose the account that's syncing the contacts and turn off the button for Contacts. This will stop them from syncing to your iPhone.

Regards.