Phantom Roaming

Phantom Roaming, sometimes also referred to as Ghost Roaming, is a very annoying phenomen that occured first a few years ago. Some users are still not aware of it and others do notice it, but don't know what to do. That's why this article deals with this feature in detail.

What is Phantom Roaming?
Phantom Roaming was first seen by users who found mysterious mini-debits on their monthly bill while roaming abroad in a 4G/LTE network. As 4G/LTE roaming was at beginning only accessible to postpaid customers, they were the first to be hit.

The phone company charged them very small amounts of data that simply didn't make sense. Furthermore, these users were totally sure to have shut off all data roaming before on their device. They knew about the potential costs involved and we have recommended them to do so in this wiki. Yet they were charged repeatingly for very small data connections that still added up to a considerable amount on their bill. Later prepaid customers reported the same dwindling of their balance.

So when you roam abroad especially in expensive countries using a 4G/LTE-enabled device, check your bill (when on postpaid) or your data balance (when on prepaid) for charges that occured during your stay, even if you have shut off all data roaming. The phone companies know the problem by now and normally reimburse your loss, but you have to apply for it. They could easily filter out all these unintentional data connections by their billing system and don't charge them at all, but most of them still give it a try. And many users don't know what to do. Some operators actually blame the user or the device for this.

What's the reason for Phantom Roaming?
In the early days of LTE roaming not so long ago the operators came away with it, because the reasons remained unclear. This has changed now and all operators know.

As it turned out a bug in the LTE protocol is responsible that some phones on 4G/LTE keep sending data to the roaming network, even when data roaming has been disabled before. This can happen quite frequently or in special occasions when you have logged off from a WiFi network and a 4G/LTE mobile roaming network is available. Some devices seem to be more susceptible than others, but it also depends on the home network operator and the roaming network.

You can only be affected when using a 4G/LTE device with a 4G/LTE plan enabling 4G/LTE roaming on a foreign 4G/LTE network. So the problem is limited to 4G/LTE, it doesn't concern any 2G or 3G. There seem to be more Apple devices involved than Android smartphones, but it's not limited to iPhones.

How to protect against Phanton Roaming?
Here are some simple steps to prevent Phantom Roaming in the future when you are abroad: You can shut off your device as well or take out the SIM card, but most users want to stay connected for incoming calls and texts on their usual number. That's why a total blackout is a bad solution for them. Some providers offer to shut off all (data) roaming by default through customer support. This again is inconvenient in countries like within the EU where cheap international roaming has been established for which data roaming should be easy to enable.
 * it's not sufficient to only disable data roaming on your device while being abroad (outside a roaming zone)
 * you need to disable all data transmissions (mobile internet, not only roaming)
 * and additionally disable all 4G/LTE networks

You can do without as long as you stick to 2G or 3G networks only, which are sufficient for incoming voice calls or SMS. On all devices disable all (not only roaming) data completely and shut off 4G/LTE. On Apple devices you can specifically block 4G networks by disabling 4G networks at data options. On most Android devices with LTE you can do the same by resetting the network connection type to 2G or 2G/3G only.

If you don't want your phone to be connected to your home SIM at all without switching it off or taking it out, you can also leave it in flight mode to use WiFi connections for data only.

If you have an Android Dual-SIM phone you can be pretty safe from Phantom Roaming as long as you assign the slow secondary SIM slot to your home (roaming) SIM on 2G or 3G only and the primary 4G/LTE slot to your local data (and voice) SIM.

It can only be hoped that this bug in LTE will be fixed soon with new devices not susceptible anymore to Phantom Roaming as LTE becomes through VoLTE the core network technology of mobile internet.