Choosing the right eSIM package and understanding where and how you use it can change your world as you explore it, whether in Paris for the Olympics or London for strawberries and cream at Wimbledon.

“Bill shock” may sound like something that happens to a duck caught in an electrical storm or toaster, but it has nothing to do with any of these things.

While there may be wild flapping involved, it’s very much of the human variety.

What bill shock refers to is the astronomically high data roaming charges international travellers incur during their time abroad.

One poor Irishman – no doubt even poorer now for his troubles – was slapped with a €91 000 (R1.7 million) bill after a seven-day jaunt around Europe. This all came about after the unfortunate man exceeded his roaming limit, according to a report by the UK’s Daily Mirror.

Now, imagine you’re a South African tennis fan whose biggest dream is to watch a Wimbledon final (and let’s face it, there are many of us). Not impossible but be prepared to fork out a cool $16 000-plus (R297 000) for the six-day tour package in London should you book through Grand Slam Tennis Tours.

Now, picture a scenario where you have no choice but to go all in on the expensive, fully open data roaming option on your mobile network because the work piling up back home doesn’t care about your dreams.

Simply put, whatever best life you may be living at centre court or alongside Italy’s beautiful routes will be painfully short. Even the saying “out-of-pocket” won’t do justice to the kind of financial strife you’ll be in.

Most people know that data roaming costs are high but do not know why. The reasons are severalfold.

When you use data abroad, your home network must pay the local network for using its infrastructure. These costs can be steep. The systems managing these transactions are also outdated and lack transparency, often resulting in unclear and obscure charges.

Managing different regulations and taxes across countries adds complexity and cost, as do the administrative overheads of maintaining these international agreements. Finally, there has been very little competition, keeping prices high.

Of course, knowing this won’t help, but it does explain why the rise of embedded subscriber identity module (eSIM) technology is proving such a game-changer.

According to Mark Collie, CEO of South African-born global eSIM service provider KnowRoaming, travel eSIMs are an innovation in roaming, where providers can offer fixed, affordable rates for destinations, bypassing high roaming fees.

“These eSIMs are generally pre-paid, providing consumers with clear and transparent upfront costs before they travel, without any hidden fees or bill shock upon their return home,” he says.

Returning for a minute to the South African-at-Wimbledon example, say the fan has found some Saffer friends to stay with and decides to spend two weeks in London, also taking in the sights.

For an eSIM data plan of 5GB for 15 days, they will pay R273. If they went the traditional roaming route, they would pay around R1 400 for only 10 days’ worth of the same amount of data.

That is a significant saving, whichever way you look at it, and if you’re a South African panicking over every murmur in the exchange rate, it’s absolute gold.

That is not to say that you shouldn’t be careful about your data usage, Collie advises.

“Navigational apps like Google Maps can use a lot of data, so it’s often a good idea to download maps for the area you’ll visit. Streaming apps like YouTube and Netflix (250-500 MB per hour) are also data intensive.

“Checking data usage statistics on your phone can give you an idea of how much data certain apps consume and your average over time. Additionally, consider activities like video calls (1-2 GB per hour) and social media uploads and automatic app updates (50-500MB per download), as these can also contribute significantly to data usage.”

Long story short, eSIMs are the way to go for South Africans travelling to sporting events like Wimbledon or the upcoming Paris Olympics.

For our sports-mad travelling fans, they are the ultimate solution.