Assalaamu alaykum, dear Shaykh. A scholar was asked about exchanging two mobile phones for one, and he said that there was nothing wrong with that and that it does not constitute interest because these things are not part of that category. However, recently, another scholar was asked about exchanging two bottles of cold drinks for one, and he replied that it is not allowed.

All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallahu ‘alayhi wa sallam, is His slave and Messenger. 

There is no harm in exchanging one mobile phone for another or more because mobile phones and similar commodities are not subject to this kind of interest. The same applies to exchanging one empty bottle for one or two bottles.

Riba Al-Fadhl (usurious surplus) is applicable to four categories: pricing commodities (which can be used to estimate a price: money, gold, silver, etc.), edible commodities, what is sold by measure, and what is sold by weight. Mobile phones do not fall into any of these categories, and accordingly there is no religious impediment to exchanging one phone for one or two phones.

As for what the other scholar said, then perhaps by ‘bottle’ he meant the drink inside it, and not the empty bottle. There are details regarding drinks, so you should refer to the details that the scholars mentioned about drinks. If you can ask the scholar himself what he meant in order to clarify it to you, then that would be better.

Allah knows best.