“My charger didn’t work abroad” is almost always a mix-up between two genuinely different pieces of travel gear, not a faulty adapter. A plug adapter and a voltage converter solve two different problems, and confusing them is the actual mistake behind most of these stories. Before a resort trip to Mexico or the Caribbean, or the flight home to Australia, it is worth five seconds per device to check which one you actually need.

Adapter: shape only

A plug adapter changes the physical shape of your plug so it fits a different country’s wall socket. It does nothing to the electricity passing through it. Voltage and frequency go through completely unchanged. If a device is only built to handle your home country’s voltage, a shape-only adapter will not protect it from a voltage mismatch abroad. It only makes the plug fit the socket.

Converter: voltage only

A voltage converter does the opposite job. It steps the actual electrical voltage up or down between what the wall socket supplies and what your device is built to accept. This is the piece of equipment that matters when a device genuinely is not built to handle your destination’s voltage. According to the classification maintained by the International Electrotechnical Commission, voltage varies meaningfully by country: roughly 100 to 127 volts across North America, Mexico and much of the Caribbean, versus roughly 220 to 240 volts across Australia, New Zealand, most of Europe and much of Asia. A traveler going from Sydney to Cancun is moving from the higher-voltage group to the lower one, and the same question applies in reverse on the way home.

The one check that tells you which you need

Look at the input rating printed directly on the charger or power brick itself, not the device. Most modern electronics, phone chargers, laptop chargers and most camera chargers, are dual-voltage, built to safely accept a wide input range, commonly printed as something like “Input: 100 to 240V.” If a charger states a range like that, it already handles the voltage difference internally, and a plug adapter alone is genuinely sufficient. No converter is needed, regardless of which direction you are travelling.

A charger that instead states a single fixed voltage, something like “Input: 120V” or “Input: 230V” only, is the one that genuinely needs a voltage converter when travelling to a country with a meaningfully different supply. This is far less common on electronics than it used to be, but it still shows up.

Where this actually catches travelers out

High-draw appliances are the most common mismatch, specifically hair dryers, hair straighteners and travel kettles. These are more often single-voltage than phones and laptops, partly because building a high-wattage dual-voltage heating element is more expensive than doing the same for a low-draw phone charger. A resort hair dryer packed from home for a Mexico or Caribbean trip is one of the more common items that either fails outright or underperforms badly on a lower local voltage, which is one more reason most resorts in our coverage provide one in the room rather than relying on guests to bring their own. It is worth checking what to pack for a beach resort trip before assuming a high-draw appliance needs to come with you at all.

Checking the plug shape for your specific destination

Beyond voltage, plug shape itself varies by country, and some countries use more than one type depending on the building or its age. The IEC maintains an official letter-coded classification, covering types such as A, C, G and others, along with a database of which type each country and territory actually uses. Mexico, the Dominican Republic and most of the Caribbean resort corridors use the same flat two or three-pin plug as North America, commonly called Type A or B. Australia uses the distinctive angled three-pin Type I plug, which is different again. Checking the IEC’s own reference for your specific destination is more reliable than assuming from a general regional memory, since exceptions exist even within regions that mostly share one plug type.

What this means for a resort trip specifically

Most resort rooms in Mexico and the Caribbean now include at least one US-style outlet alongside any local variant, since the region’s tourism infrastructure is built heavily around American and Canadian visitors who already use that plug shape. A single universal travel adapter covers the shape problem for nearly every device most guests actually pack. The genuinely useful habit is checking the input rating printed on your own chargers before you leave, particularly for anything with a heating element, rather than assuming every device behaves the same way as your phone. Pair that with staying connected more broadly, covered in resort wifi and staying connected while you travel, and the only item worth double-checking before departure is whether your specific hair dryer or straightener is actually dual-voltage, not whether your phone charger will survive the trip.