Talk:Italy/@comment-24.167.164.197-20190403155500/@comment-24682153-20190403160807

No, it's a hit and miss. You can generally assume that all subsidiaries roam like their network parents. Vodafone uses mostly other Vodafone networks or partner networks. The list of TIM and Wind/Tre is often very similar, but evades mostly Vodafone networks and prefers Orange, Telekom and others instead.

For instance in Germany Vodafone Italia roams on Vodafone DE and Telekom which is rare, TIM and WindTre on Telekom and Telefónica.

There is no reliable list as these partners sometimes change. Furthermore they may be some partners where you can roam, but not in LTE. But generally LTE availability in roaming is now pretty good with Italian providers.