Samsung Pay finally expanded its reach into the United Kingdom on May 16, and just over a month later, it is picking up support for two additional banks. The service now accepts credit and debit cards from six banks in total, but there are still some big omissions.

As of today, customers who use HSBC, First Direct, and M&S Bank can add their cards to Samsung Pay. When the service made its debut in the U.K., the only supported card issuers were MBNA, Nationwide, and Santander. Today's update doubles its reach, but just one of the "big four" are on that list.

Barclays, Lloyds Bank, and The Royal Bank of Scotland are still missing, as are others like Natwest, Halifax, TSB, and Standard Chartered. Money-lenders like American Express, Capital One, Ocean Finance, and Vanquis Bank are also nowhere to be seen, though some of these names — such as Barclays — are also missing from Android Pay and/or Apple Pay.

As we know, however, the rollout of mobile payment services is a typically slow process. Samsung Pay was never going to land with support for all major banks and money-lenders right of the bat, but Galaxy smartphone owners will be keen to start using the service now that it has landed in the U.K. There's no word from Samsung on when others might be joining the service.

Samsung Pay is available on all of the company's flagship smartphones from the Galaxy S6 and S6 edge, as well as the Galaxy A3 and A7. The South Korean company promises to extend support to additional devices "in the coming months."