i have a locked 02 phone that I want to use on GiffGaff will it work on all the settings without me getting it unlocked.
Yes it will work as Giffgaff piggyback off o2. I've used an o2 phone myself without needing to unlock it.
A word of caution @ellisonmw , if it is a Tesco Mobile phone it will likely be double locked, to O2, the parent network and also toTesco's network.
In that case, a giffgaff SIM will only work if the Tesco lock has been removed.
My transfer from another network is due on the 27th. How long will it take to port to gg