A Field Review of the OneSimCard

Note: There’s an update to this post. More information for 2014 is here!

I recently traveled to Europe for business, and wanted to stay connected with my family and friends in the US while I was over there. And since I have a smartphone, I also wanted to have affordable data access at good speeds. After a little research, I stumbled upon the OneSimCard as a possible solution. It’s a SIM card solution that gives you a Estonian phone number and utilizes roaming arrangements to keep costs down in a lot of different countries (according to their site, they cover more than 200!). It was a great solution to my needs, but watch that meter closely!

While I can only provide a review based on my experience in Belgium, I can tell you that it works pretty well if you need the trio of voice, SMS, and data without looking for local, carrier-specific cards. Here are the things you’ll need to get started with the OneSimCard and your iPhone 4S:

  • an unlocked iPhone 4S (my carrier made me jump through some hoops but it got done just fine, see the link below for more information)
  • the micro-SIM card itself from OneSimCard (may be harder to find locally, so order online).
  • a pin, paperclip, or tool to eject the iPhone micro-SIM card tray.
  • a place to stash your regular carrier’s micro-SIM card.

Paying for OneSimCard usage

The OneSimCard product uses a pay-as-you-go system, meaning that you need to get set up with a balance before anything else. My card came with US$10 preloaded, but I expected to charge way more than that. While I was in Belgium for 5 days, I:

  • made about 38 minutes worth of calls that cost about US$22,
  • used about 56MB of data access that cost about US$46, and
  • sent 9 SMS text messages that cost about US$4,
  • which came to a total charge of US$72 in roaming fees.

I can’t recall my exact data usage, but I’m certain that, data-wise, I only sent a few emails, used Foursquare, viewed a few mobile sites, and uploaded a picture or two. At about $0.82 cents a megabyte in Belgium, be very careful about your apps and web access. As an alternative, be aggressive about finding WiFi hotspots that you can use safely. It’s more of a convenience thing than a good value, considering that data roaming rates vary across countries. As you travel, it’s fairly straightforward to add funds right from your phone as long as you set up “Automatic Recharge” or a balance in the “OneSimCard Money Fund”.

Activating the OneSimCard for use

Another nuance of the OneSimCard product is its activation steps. The procedures to get set up are scattered across the site but they are fairly straightforward themselves. To make it easier, I’ve compiled a quick walkthrough to handle calling, texting, and data access in the next two sections.

1. Setting up “compatibility mode” for calling and texting

Compatibility mode eliminates the need to prefix your calls with the string “*146” for the majority of phones, and apparently is a requirement for the service to work on iPhone 4S devices.

To do this, on your iPhone, go to
1. Settings > Phone > SIM Applications > OneSimCard > Settings which is located at the bottom of the screen.
2. Agree with the resulting message message by tapping “Accept”.
3. Dial “1101”, and tap “OK”.
4. The screen will show “CC OptionX: ON” message.

2. Setting up GPRS data access

If you’re interested in using data access (accessing websites, online services, etc.) like I am, then make sure to go through these steps as well.

To get GPRS set up on your iPhone, go to
1. Settings > Network > Cellular Data Network
2. Set the APN field to “send.ee” and the User Name field to your Estonian cell phone number “3725XXXXXXX”
3. Turn Data Roaming to be “On”.
4. Reboot your device after putting in these settings.

Incoming and Outgoing Calls

The last thing to know about OneSimCard is its calling procedures. Unless you want to pay extra for a “Personal Extra Number” (or PEN) which allows folks from home to dial you directly using a local number, there are “Common Access Numbers” that folks can use to get in touch with you. The Common Access Numbers are numbers you can dial without incurring international charges before dialing your party. I found that the easiest way to set up friends and family were to help pre-program their phones with the CAN, a 4-second pause, and then my OneSimCard number. You’ll find a list of these numbers in the OneSimCard User Guide (see the link below). Otherwise, if folks call your OneSimCard number directly, they need to be prepared for extra charges if you haven’t set up a PEN (which itself is a monthly US$4.99 charge at the minimum).


As I mentioned before, the OneSimCard turned out to be a great solution to my needs. It was a highly convenient way to stay connected. However, it has certain caveats that you have to bear in mind in terms of cost, setup, and incoming calls. If you travel internationally to a range of countries, the OneSimCard should be high on your list. However, if you only end up travelling to a limited set of countries, it might be worth looking for cheaper alternatives.


Where’s Estonia? http://en.wikipedia.org/wiki/Estonia
Unlocking a Verizon iPhone 4S through customer service: https://community.verizonwireless.com/thread/696707?start=0&tstart=0
OneSimCard: http://www.onesimcard.com/
OneSimCard data rates: https://www.onesimcard.com/cell-phone-rates/
OneSimCard user guide: http://www.onesimcard.com/doc/OneSimCard-User-Guide.pdf
Removing your iPhone micro-SIM card tray: http://support.apple.com/kb/HT1438

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