How do I delete a call or message from the history

° On iOS:
Slide your finger on the line of the call or SMS conversation from right to left to reveal the "Delete" button.

° On Android:
Leave your finger on the line of the call or SMS conversation to bring up a pop-up allowing you to delete this call from your history.

° On the website:
Select the call from your call log,
Press the 3 small blue dots and then "Delete call".

Deletion is definitive and irreversible.
It is not currently possible to delete a call history en masse.