IPhone – change the LTE bands supported by the iPhone 5s

There are actually 4 different international variations for the iPhone 5s/5c. Thankfully, Apple has a page outlining them with their model numbers, supported frequencies and countries/carriers you can use them with.

A quick look over that breakdown seems to suggest that Belgium (at least, Mobistar) uses LTE bands 1, 3 or 5, which the US AT&T model also supports. However, I would recommend you contact your carrier to ensure what frequencies are needed to function best on your network.

In a word, the problem is 4G. There are simply too many different 4G frequency bands for any one phone to support them all -- the iPhone 4s doesn't support 4G at all, and so it doesn't have this problem. The iPhone 5s has to have different models that support the frequencies used in different parts of the world.

If you don't care about 4G and just want GSM or CDMA, then this shouldn't matter to you. You can just buy any GSM or CDMA model, and it will work just as well as the iPhone 4s GSM or CDMA model.

If you do care about 4G, then look at this page and pick the model that supports the 4G network that you plan to use it on.