However, the proportion of M2M connections accounted for by roaming is growing even faster.

As a global provider of roaming services including billing and clearing to network operators, Starhome Mach is able to determine that the number of roaming registrations that can be attributed to M2M devices increased by 100% last year to reach 7% of all roamers. The rate of growth is such that it is entirely possible that there will be as many machines as people roaming by 2020.

Despite the hostility of some regulators, ‘permanent roaming’ remains an important way of serving multinational customers in M2M, many of whom want to deal with a single provider. This is particularly the case for global manufacturers, who don’t want to provision their products with a different SIM depending on the destination to which they are being shipped.

Permanent roaming also enables M2M devices to obtain better coverage – the sum of all available networks in a ‘visited’ country – which would not be available to a purely local SIM in the absence of extensive agreements for national roaming.

An operator that wanted to provide smart metering services to a utility company, for example, would find that using SIMs from a foreign operator would deliver better coverage than using its own local SIMs.

Most roaming SIM cards do so specifically to take advantage of these two benefits: supply chain simplicity and best coverage. Curiously, devices that actually cross borders, i.e. the archetypal roamer in the more established devices, are the least significant source of M2M roamers.

Jeremy Green, Principal Analyst at Machina Research, said: “Network operator need to be more aware of what is happening with both inbound and outbound roaming M2M devices. Without such insight it’s hard to see how they can optimise service for their customers, meet regulatory requirements, or ensure the smooth and reliable functioning of their networks and international services.”