If any US Sony fans were wondering exactly which variant of the Xperia Z5 Sony plans to launch next month, then a placeholder listing from B&H Photo has the answer. It confirms that it will be selling the E6603 model, which has most of the necessary bands to support AT&T and T-Mobile (the latter lacks 3G support on 1700MHz).
In terms of band support it carriers the same frequencies as the E6653 variant, which we recommended in our USA Xperia Z5 Buyers Guide as the one to go for. The big difference between both variants is that the E6653 supports LTE Cat 6 speeds for 300 Mbps download, whilst the E6603 only supports LTE Cat 4 speeds (up to 150 Mbps download). The US Xperia Z5 is due to launch in the country on 7 February 2016.
Xperia Z5 E6603 frequency support
UMTS HSPA+ 850 (Band V), 900 (Band VIII), 1900 (Band II), 2100 (Band I) MHz
GSM GPRS/EDGE 850, 900, 1800, 1900 MHz
LTE (Bands 1, 2, 3, 4, 5, 7, 8, 12, 17, 20, 28, 38, 40)