First there was the regular SIM card, then the micro SIM card. Now, nano SIM has become more or less the standard for the smartphone market (especially among the best-sold models), but the next generation of mobile connectivity tech is looming. And in fact, it’s already here.

What is eSIM, exactly?

As the name implies, eSIM refers to a new kind of SIM technology that works electronically. In other words, this type of SIM card is already integrated into the device, so it can’t be psychically removed (nor does it need to), like we usually do when changing to a new phone.

Instead, the eSIM’s information is compliant and completely rewritable by all mobile operators, meaning it can change phone numbers instantly with a simple phone call. At this point, we could be saying that it is the phone itself that can change numbers, as the user will never have to deal with anything “SIM” related again.

eSIM is not exactly new, as there are some products that are already using it, like several LTE-supported tablets and smartwatches. Most notably, Google’s Pixel 2 phones support eSIM on the company’s own Fi network, the first smartphones to do so.

The tech is very attractive for manufacturers, as it allows them to free the space required for inserting a SIM card and repurposing it for more interesting things. However, there’s also great benefit for the users, including one that could radically change the way we travel.

A great Benefit for consumers… maybe

One of the great many things eSIM could bring would be the end of roaming as we know it. Up until now, using roaming services has not only been overly expensive for consumers, but also an extremely cumbersome process. In a hyper-connected era, it’s common to still travel without using roaming, and travelers often rely on Wi-Fi to stay connected.

Recent initiatives like the EU’s free roaming regulations are hugely beneficial, but still exclude travelers coming from and going to the US, as well as other countries. eSIM could bring in a new era of low rates and far less complications, according to a report published by Uni-fi Roaming Solutions (UROS).

UROS Program Manager, Mika Alamartimo, argues that there are several reasons why the technology could bring in those favorable changes. For one, the ability to change phone numbers with ease could open the doors to visitors being treated as local customers so they can receive the same competitive pricing.

UROS also cites the increasingly common “roam like at home” regulations, like the previously mentioned one in the EU, as proof that consumers are not willing to pay overpriced rates when traveling. Some operators, like Vodafone in Spain, offer roaming for the US at no extra cost, though the majority still charge overpriced rates.

However, it’s also fair to admit the idea is a bit utopian. Although changing numbers now would be a much easier process, carriers do offer plans for travelers when they’re in the country. eSIM removes the need to go to a store and change SIM cards, but the overpriced rates are still there. Time will tell if the market will autoregulate itself.

A slow burn

There’s a small catch to all of this: it won’t be overnight. Even though the report offers an optimistic view of the roaming landscape in a relatively short period of time (eSIM will dominate in 3-5 years), it also recognizes the fact that it will be a long process.

UROS doesn’t expect an eSIM-supported iPhone until 2019, for example. And that goes the same for more manufacturers. Additionally, eSIM will be prominent soon, but the report expects regular SIM technology to also coexist with it for a long time.

eSIM is already here to stay, but the road to a single standard is a bit farther away. It’s also a matter of resources that need to be invested in by the industry. But that’s true of every new technology in every sector, and this isn’t the exception.