The stickiness strategy: why banks are bundling in mobile connectivity

Alice Whitelam, Senior Consultant at KAE, explains why banks are increasingly bundling mobile connectivity into their offerings, and what it means for the future of banking.

Santander's new eSIM is the clearest sign yet that connectivity is becoming a mainstream banking product, rather than a challenger experiment.

On August 3, 2026, Santander launched an eSIM service in Spain, built with the connectivity platform Gigs and sold directly inside the bank's app. Customers buy international data packages ranging from 3GB to 50GB, use them across more than 160 countries, and manage consumption in their daily banking app. Portugal and Mexico are set to be next, with further Santander markets to follow. The bank has positioned it as part of a wider effort to build scalable digital services across the group, aimed particularly at frequent travellers, younger customers and those who already do most of their banking on a phone.

Santander has not acted in isolation. Over the past few years, a growing number of fintechs and digital banks have started offering embedded SIMs, or eSIMs, inside their apps. Phone connectivity used to sit entirely with telco providers, now it turns up next to your bank balance, card controls, and spending analytics. The convenience on offer here is undeniable, but it gives a glimpse into how digital finance companies think about growth, data, and the relationship they want with their customers.

Why are banks adding mobile phone plans to their apps?

The practical appeal is easy to understand. An eSIM is a chip built into the handset rather than a small piece of plastic you slot in and hope not to lose. Adding a plan takes a few taps, and you can hold several profiles on one device at once. For anyone who travels regularly (or for the increasing number of digital nomads among us), that removes the familiar chore of hunting for a local SIM on arrival, keeping track of the original one, or accepting whatever roaming rates apply. Switching networks becomes a simple setting switch, which explains why uptake has been significant.

What is perhaps less clear is why a company whose core business is payments, deposits, or lending, is now the one offering such a service. There are various answers to this:

A traveller is already a high value customer for a bank. They spend abroad, exchange currency, and lean on the app to check what has just been charged. Selling data to that same traveller is a natural progression, and if someone is opening the app in an airport or during travels anyway, offering connectivity at that moment is well timed.

Engagement is another layer. Financial apps are typically seen as just that, and are often therefore not opened with much frequency. A service customers need on a specific trip, on a specific day, gives the app more reasons to be launched.

The key driver, which is hard to ignore, is data. Fintechs and banks alike are no strangers to data, with transaction histories creating a footprint of a user’s daily life. Mobile connectivity widens this understanding – which country a customer is in, which networks they are attached to, and how they are using the devices. Used well, that information supports things customers actively like. Travel notifications that arrive before a card gets declined, currency suggestions at the right moment, insurance or trip products offered when they are relevant rather than at random. Personalisation of this kind is one of the clearer advantages digital providers can create with increased data.

The strategic layer at play

There is a strategic layer at play here too, and it is one that we have seen before outside of finance. Apple and Google are the obvious reference points, having spent decades showing that the customer relationships with the most longevity are the ones with the most threads running through them. Each extra service makes the bundle harder to leave as unpicking it is a nuisance, fuelling the inertia. 

Fintechs offering connectivity are moving in that direction. A customer whose account, card, currency exchange, subscriptions, and mobile data all live in one app has more to reorganise if a rival launches something better. The friction of switching rises as more products intertwine.

Southeast Asia offers one example of this consolidation of products. Grab, based in Singapore, began as a ride-hailing app and now has 54 million monthly transacting users, having added payments, lending, and three digital banks along the way. It holds USD 2.3 billion of loans on its books and USD 2.5 billion sitting in customer deposits. In October 2025 it opened its app to outside providers, and one of the five launch partners was Firsty, an eSIM service covering more than 180 countries. Mobile connectivity now sits alongside taxi services, takeaways, and financial services. Grab has reached financial services by starting with daily life, while Santander is the latest to reach daily life by starting with financial services. The potential outcome remains the same.

Japan offers a similar example. Rakuten began as an online marketplace, before building one of the country's largest online banks with more than 18 million accounts, and then built a mobile network, which passed 10 million subscribers at the end of 2025. The two now operate in a kind of symbiosis –

since February 2026, customers who take a Rakuten Mobile plan earn a higher rate of interest on their bank deposits. Connectivity is extending beyond a product sitting in the app, becoming a reason to keep the money there as well.

Which non-financial products belong in a banking app?

The broader question facing banks is which non-financial products, if any, belong inside their app – travel cover, subscription management, loyalty offers, mobility, energy switching, and connectivity all follow the same logic. Bundling works when the added product matches how customers already live, which means knowing which segments have the need, what they currently use to meet it, and how much cost or hassle they will absorb before looking elsewhere.

That answer shifts by market, age group, life stage, travel preferences, and spending habits. Transaction data alone will not settle it, because it shows what people did rather than why they did it. It rests on understanding customer priorities and trade-offs, segmentation, willingness to pay, and proposition preferences, so that what launches is shaped around what people value rather than what is technically possible to bundle.

The merging of finance and connectivity looks likely to continue. As more of daily life runs through a phone, the line between the app that holds your money and the service that keeps it online becomes harder to justify. It is likely a matter of when, rather than if, more incumbent players follow suit.

About the author

Alice has over four years of experience in the payments sector, helping clients identify market opportunities and unlock them through value proposition optimisation, consumer sentiment analysis, and competitive landscaping. She has led high-impact projects delivering actionable strategy on user experience and customer sentiment in financial services. 

 

About KAE

KAE helps banks, payment companies, and fintechs around the world make data-backed marketing, product, and strategy decisions by uncovering deep customer, market, and competitor insights. For over 30 years they have provided market-leading businesses with the customer and market intelligence needed to shape and execute go-to-market strategies, develop products and experiences, optimise pricing and communications, and build effective sales and partnership ecosystems.