Erika Kullberg, an attorney who studied at Georgetown Law, explained that when buying things overseas, it's important to purchase them in the local currency and not U.S. dollars – because stores will often charge an extra fee to pay in USD, and give you a bad conversion rate.

Erika warned her followers about the ‘trick' in a TikTok video, which has now gone viral – gaining more than three million views in a matter of days – and many people were thankful for her advice.