Tourist left in utter shock after receiving a $143,442.74 bill for three-week Switzerland vacation

Many of us know that we need to be wary of roaming charges when traveling abroad.

Going on holiday often involves diving into the small print of your phone's data plan to work out whether you have roaming included, and if not, how much it'll cost.

One Floridian reportedly got the shock of his life when he got back from a three week holiday in Switzerland to discover that T-Mobile wanted just over $140,000 of his money.

Hadi Zaher / Getty

Rene Remund, 71, from Dunedin, Florida, actually saw this problem coming - he told ABC Action News he went to a T-Mobile store before going on holiday to Switzerland with his wife.

The store's staff apparently assured him that while abroad he could use his plan as usual and was "covered".

Remund took that to heart, understandably, and took a whole bunch of photos while in Switzerland, and sent plenty of those photos to friends and family to show off his trip.

He thought that would be the end of it, but when he got home he reportedly got an absolutely hair-raising bill, accounting for the 9.5GB of roaming data he'd used by demanding over an astounding $143,000 of his money.

Remund was, unsurprisingly, shocked by the bill and assumed it was a mistake. As he explained to local news site Scripps News Tampa: "I'm looking at it and I say, 'Excuse me, $143,000, are you guys crazy?"

He called up T-Mobile to try to fix what he assumed was an error, but was told that the bill was accurate and there was nothing to do but pay it.

Remund instead instructed a lawyer, who wrote letters to various T-Mobile addresses and spokespeople without getting any responses.

David McNew / Getty

However, when the attorney told Scripps News Tampa about the bill, and it got some coverage, it looks like T-Mobile offered to credit his account for the whole bill.

Still, in a statement to Scripps News T-Mobile reminded people about best practice when going abroad: "We recommend our customers check the travel features of their plan, such as international data roaming, before departing ... if a customer is on an older plan that doesn’t include international roaming for data and calling, they’ll need to make sure they’re using airplane mode and wi-fi when using data to be certain the device doesn’t connect to an international network."

So, if you weren't already being super careful about roaming charges before reading this, make sure you are now - because a $143,000 bill out of nowhere is the sort of thing that would ruin most holidays.