
Last month, the European Telecommunications Standards Institute (ETSI) gave the green light to Apple's nano SIM card. The new card provides the same functionality as the current SIM cards, but is significantly smaller in size.

According to a new message released yesterday afternoon, European mobile operators expect Apple to use the new nano-Sim cards in the iPhone 5. And they have already started stocking up on them ahead of a product launch this fall …
As reported by the Financial Times:
In recent years, carriers have been caught off guard by the decision to use micro-SIM in the iPhone 4, and, accordingly, have not been able to meet demand in the first weeks of sales.
One informed source, who wished to remain in the shadows, told the agency that large operators do not want to be in a similar situation this time. He added that the iPhone 5 is likely to be the same size as the iPhone 4, but thinner and metal.
It certainly won't surprise us if nano SIMs appear in this year's iPhone modification. Early reports suggest that Apple engineers have gone through a lot to make the smartphone noticeably thinner than its predecessor.
The recent leak also confirms rumors that the SIM card slot in the upcoming model is significantly smaller.
The new modification of the iPhone this year will be the sixth generation of the popular gadget. It is expected that in addition to the new design, the smartphone will be equipped with a large display and compatible with LTE networks.