Talk:United Kingdom/@comment-75.177.66.190-20160711211233/@comment-3564598-20160712100903

First off, Verizon will charge you $10 daily to use your US plan in the UK. For one month that means around $300. There are many, many options that will cost less if you get a local SIM. Even EU roaming from another country would cost less.

First off, you mentioned O2. They do not have the best reputation in the UK. I was warned away from them when I went last month. That said, I had no problem using Tesco Mobile (MVNO on their network) aside from finding a SIM. I ended up going to six different Tesco stores in London before finding one that stocked the SIM. I would expect O2's own SIMs to perform well also.

That said, do look into each provider's international voice rates; if you plan on making calls the traditional way, rather than with Google Voice/Skype/etc, then this may be the deciding factor.