Iphone 6

[sbrown1450]

I have upgraded my phone from an IPhone 6 and want to clear all my private information off the old phone.
Guru at O2 said to set phone to factory settings and then no-one can get bank details etc from the phone.
But in reading some replies to similar questions it says this does not work.
What do I need to do? I have no sim in the old phone at present.

[woofgang]

could you post a link to those "similar questions" where the reply has been that this doesn't work please as I have always done this and never had a problem.

[Guilbert53]

If you search on "Factory reset an iPhone 6" there are numerous web sites which explain how to do it.

Here is one as an example (I have not tried it)

https://www.digitaltrends.com/mobile/how-to-factory-reset-an-iphone/

I am sure there are probably YouTube videos as well that explain how to do it.