Unlike a lot of countries, the UK has free and near-instant bank transfers which seem to be a de facto standard for things like splitting bills with friends.
Incidentally I tried to use Venmo while in the US, but the app was geo-blocked so I couldn’t install it with a Google Play account set to the UK.
Interestingly, you might actually have that a bit backwards - North America is the only place I know of that doesn't have free (or with a fee of a few cents), near-instant bank transfers. It actually surprised me how backwards the banking system seemed the first time I was in the US (coming from West Africa).
Incidentally I tried to use Venmo while in the US, but the app was geo-blocked so I couldn’t install it with a Google Play account set to the UK.