Phone Not Compatible With Contract Sims?

Tom_129

Honorable
Jul 25, 2016
26
1
10,545
Basically, I bought a budget phone online and when it arrived, it worked well on an old O2 Pay As You Go sim card that was in a VERY old phone, but of course I want to get a new sim from a different provider. However, according to the phones amazon page, (or an amazon page at least), the phone isn't "compatible with contract sim". (The English is broken because I think it's a Chinese phone). Not sure if this is the right place to post but hey, it's close enough. Any help, guys?
https://www.amazon.co.uk/gp/product/B01FH860G2/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1