The way we stay in touch, do our shopping, and even the ways in which some of us find love, have all gone digital. Yet, for the vast majority of people sending money home to friends and family in Africa, they are still doing it the way they have always done it: in cash.

One and a half million people in the UK send over four billion pounds to Africa every year. Nine out of ten of these transactions are carried out using cash and only one in twenty is initiated online. It seems the that convenience and cost saving of using digital methods has failed to do what economists would have predicted: incentivise a meaningful change in consumer behaviour. But why?

The UK remittance market is generally considered competitive, with multiple providers offering a variety of services. Overall, the average cost of sending money from the UK around the globe is almost 8 percent, only slightly more than the global average of 7.5 percent. But when it comes to sending money from the UK to Africa, the average is much higher, at almost 9.5 percent. And this figure conceals an even deeper divide. Want to send money to Kenya? That’ll be 7 percent. But want to send money next door to Tanzania? That will be twice as much.

Another key divide is not where you are sending your money to but how you are sending it. On average, the cost of making a cash-to-cash transfer from the UK to Africa is over 11 percent. What that looks like in practice, is, for example, an Ethiopian going to an ATM in London, taking out cash and walking up the high street to hand it over the counter of a money transfer operator. Later, in Addis, their sister goes to a counter and receives that cash (minus 11 percent) in her hands.

Yet, go online and you can cut the cost to 8 percent and if you send it to a mobile money wallet it can cost just 6 percent – a difference of almost half! What does that look like? A Kenyan in Birmingham does a bank transfer or uses the details of their debit card to send money online. Later in Mombasa, their mother receives an SMS saying that the money is now in her M-Pesa wallet (minus 6 percent).

There is a wide range of providers who offer these digital services to customers in the UK. They include the traditional money transfer giants like Western Union and MoneyGram, as well as newer market entrants such as Azimo and WorldRemit. These digital services offer what we in the remittances policy world call a more “streamlined value chain”, by removing the need for agents.

Agents typically take around 25 percent of the total fee plus the foreign exchange margin at both ends. As well as removing the agent, digital service providers can also take advantage of technology such as facial recognition technology and fingerprint reading, to reduce the risks involved in the transaction.

Cash services are also becoming increasingly challenging and expensive to manage in the UK. Even the Post Office is going digital and other cash deposit-taking institutions are also closing their services to money transfer operators, making cash collection more difficult, and banks are increasingly hesitant to offer bank accounts to cash-based money transfer operators.

And yet, a strong preference for cash stubbornly remains. In many countries, this is attributed to the fact that senders of money remain unbanked. But a survey by the World Bank with UK migrants showed that more than nine out of ten people sending money have a UK bank account, with seven out of ten conducting internet shopping, and around half using online banking. Almost all possess a mobile phone, with most having a smartphone.

So, what’s going on? Prices for those willing to convert to digital options should be encouraging a switch. New digital players are investing heavily and are building trust through large marketing budgets. Yet consumer habits remain largely unchanged. In fact, the same survey found that nearly all senders – more than nine out of ten – have not changed their service provider since arriving in the UK.

So, why are people not taking advantage of online options to save themselves and their families money? What should service providers do to create the desired shift in consumer behaviour, and what communication channels should be used to best spread this message? These are the ‘£100 million a year questions’. Because we calculate that these ‘old habits’ are currently costing African remittance senders over a £100 million a year.

We aim to answer these questions through consumer research that will be conducted later this year.

A new research report on remittances from the UK to Africa will be published in June by Financial Sector Deepening Africa.

This blog was originally posted on the FSD Africa website on 9 June 2017. Leon Isaacs is CEO at Development Markets Associates.