How do you permanently delete contect from a phone?

[SantaClaus]

To my understanding, to delete content from a phone permanently, you need to delete it from the recently deleted folder, then overwrite all the free space on your phone with a long and pointless video. Phones use flash memory so once it's overwritten, it's unrecoverable. You also need to delete any copies you have on the cloud.

Are there any details I've missed here?

 

[tech3475]

Presuming we’re talking on device storage only, one technique I’ve heard is to encrypt the phone before doing a factory reset through the settings.

edit:

This is for wiping a device entirely.

 

[YOUCANTSTOPME]

But with recovery tool, we can still recover deleted contact, if you want to permanently erase one contact from phone, use the tool , then it's unrecoverable.

If you delete it and overwrite all the empty space with junk data, then it cannot be recovered.