What is cheaper - AT&T's international voice and data plan or a local provider? The answer will obviously depend on the country of your destination. Clearly, in more developed countries you will have more luck finding acceptable local options while paying less compared to roaming charges. But in some developing regions, you may actually end up better off signing up for an international calling plan with AT&T. As a rule of thumb though, most people I know prefer using local carriers when they travel. It is very convenient to simply swap your AT&T SIM for the one of a local carrier. First you will need to request an unlock code though from AT&T.
Cost Break-down: Roaming vs. Local for UK
If you are heading for UK, here is a quick cost comparison for you to figure out if it is cheaper to use a UK carrier for your wireless needs.
Wireless Service Cost Comparison for UK
|Service/Carrier||AT&T (On Intl. Reduced Plan)||UK EE 4G (On 30-Day Prepaid)|
|Calls & Text||$1/min. + $10/50 text messages.||Unlimited Calls & Text Included in £28 Data Plan|
|Data||$120/ 800 Mb (<1Gb)||£28 (~$44) / 1Gb|
As you can see from the above cost break-down, signing up with EE - the local UK carrier - is a much better deal - hands down. It might be even worth signing up with their 30-day prepaid plan even if you are travelling for, say, a couple weeks. You will still end up saving a bunch with their unlimited texts and calls plus a GIG of data to roll when you explore the city on-the-go.
Clearly, the EE is not the only carrier in UK and its coverage may not extend to the area where you are headed (or, it may not support 4G speeds there). Therefore, checking your prospective carrier's coverage map may not be a bad idea. I remember when I landed in San Francisco and my US Cellular phone was useless there, so check everything before you go. Most carriers provide a map of their coverage right on their websites. For instance, for EE the link is https://explore.ee.co.uk/coverage-checker