On the same 65.000 € gross, a worker takes home roughly £11,819 more per year in United Kingdom than in Italy. That gap reflects the tax structure alone — before rent, healthcare, or savings behaviour come into play.
Housing is the first multiplier. Italy has moderate rent pressure, while United Kingdom has high rent pressure. That keeps United Kingdom's nominal advantage closer to a real-world advantage.
Healthcare and pensions go in the opposite direction. Italy runs a universal healthcare model — Universal SSN system, regionally administered, with private alternatives. United Kingdom uses a universal model — NHS provides universal care funded from general taxation, with private top-ups. The country with lower take-home often shifts costs that the other country leaves to your private budget.
Net-of-everything, a relocation decision should weigh strong public welfare in Italy against strong public welfare in United Kingdom, plus differences in pension capture, social safety nets, and city-level cost of living.