Comment by signal11
They've been owned by Telefónica for a while. IIRC Telefónica acquired O2 in 2006, and launched Giffgaff as a new brand in 2009.
They've been owned by Telefónica for a while. IIRC Telefónica acquired O2 in 2006, and launched Giffgaff as a new brand in 2009.