3G is being phased out by all mobile network operators, and will stop working for our data SIMs in early September. The data SIMs we provide already support 4G. In a small number of cases it is possible that devices are too old to support 4G, in which case the device is sadly obsolete and will need replacing in order to keep connectivity. You will be emailed if we think your SIM is one which is in a device still operating via 3G.
We're noticing 3G is starting to become unavailable on SIMs today (9th September)