US internet giant Google continues to add cellular features to its Project Fi MVNO, which was focused more on wifi connectivity when it was launched.

Project Fi was originally positioned as a wifi-focused MVNO, with the cellular component only coming into play when the subscriber was outside wifi coverage. It is distinctive in that it uses multiple networks – launching with T-Mobile US and Sprint – and claims to dynamically switch between them to offer the best coverage.

Google recently added US Cellular to its domestic roster but it has also been accumulating international partners to allow voice and data roaming in over a hundred countries. New international partners are not usually considered worthy of an announcement but since the Three group covers several countries, and summer holiday season is upon us, Google thought it would speak out.

“With the addition of Three to the Project Fi network, we’re now able to deliver speeds 10-20X faster than before,” blogged Tyler Kugler, Product Manager at Project Fi. “And, just as before, there are no extra fees for using data internationally – you pay the same $10/GB that you do at home.”

That’s a pretty strong offer. Even with all the various restrictions imposed by the European Commission UK operators generally charge a lot more for data roaming, even in Europe. EE wants £4 for 500MB while, Vodafone charges 4.3p per MB if you don’t have a special roaming tariff, which equates to £43 per GB! Most Three UK tariffs offer full roaming in 19 locations at no extra charge, so it’s easy to see why Google went with them.