Apple recently announced that it would make factory unlocked iPhones available several weeks after the launch of the carrier versions in the US. While the news itself is unsurprising and pricing is identical to last years 4S model, the biggest question on everyone’s mind and rightly so is the availability of nanoSIM cards for each prepaid provider in the US that isn’t Cricket Wireless.  As a result of the iPhone 5′s reduction in size and weight, Apple made a few core design changes that necessitated the implementation of an even smaller SIM card than the microSIM used in the 4 and 4S models.

Why the nanoSIM Exists

The nanoSIM card was developed by Apple in order to accommodate its needs for the smallest SIM card that would still function within the core standards managed by the ETSI (the body that manages the standards behind the SIM card and all of its variants), and its initial proposal for an even smaller SIM card standard was met with considerable resistance from competitor Nokia at the beginning of last year, who felt that a nanoSIM was completely unnecessary after the adoption of the microSIM across the industry shortly after the launch of the iPhone 4 in 2010, but was ultimately ignored and the ETSI approved the current nanoSIM and its specifications later that year.

Now that the non-CDMA carrier models of the iPhone 5 will require yet another, smaller SIM card, this will affect more than just the major GSM carriers in the US in AT&T and T-Mobile, it will also affect GSM MVNOs piggybacking off of those networks as well.

T-Mobile’s Official iPhone Support

Starting with the national carrier going out of its way to support the unlocked iPhone on an official level, T-Mobile is preparing for unlocked and international iPhone 5 availability by having its own nanoSIM cards available around the same time as the unlocked iPhone 5 officially launches in the US, with the latest estimates placing the launch for the model in mid-to-late October. As the carrier is expanding its official iPhone support across the country until the first half of next year ahead of its planned LTE launch, the carrier is hoping that enough people will be willing to buy the unlocked iPhone 5  in order to draw in new customers with unlimited HSPA+ data on postpaid agreements.

However, not everyone that wants the official support on iPhone will want to sign a new postpaid agreement, therefore the availability of the unlocked iPhone 5 will also be a boon to the carrier as the current online and Walmart-exclusive 5GB Monthly 4G plan will be extremely appealing to those that want prepaid service, along with the rest of the Monthly 4G prepaid plan lineup, which end up being cheaper than similar postpaid plans by AT&T and Verizon for individual service.

Verizon’s iPhone 5 is Unlocked (And Will Stay That Way, Thanks to the FCC)

It’s important to note that Verizon’s iPhone 5 has since been confirmed by owners and the carrier itself as being GSM unlocked for international and domestic service, which completely changes the way most potential customers would have gone with the iPhone 5. Since that version is readily available compared to the three-to-four week lead time of the factory unlocked model, it makes more sense to purchase that model outright and then use it as normal on T-Mobile due to its official iPhone support, as AT&T has no plans to support iPhone on prepaid and AT&T MVNOs have yet to confirm official iPhone 5 support of any kind.

Since the Verizon iPhone 5 ships with LTE, Verizon’s network is subject to stringent FCC regulations which prevent it from being able to lock the phone from use on other networks as a consequence of the open-access rules applied to the 700MHz spectrum it purchased and uses to operate its LTE network, which is a win for everyone.

StraightTalk/Net10/Simple Mobile: Official iPhone 5 Support Up In The Air

Simply put, StraightTalk and Net10 offer two of the best deals for GSM service in the country with $45 and $50 monthly unlimited service on either AT&T or T-Mobile, with Simple Mobile’s recent purchase by America Movil also bringing expanded T-Mobile network access to the Tracfone umbrella of brands. However, questions still remain as to how each brand will handle the iPhone 5.

While it’s expected that nanoSIMs will be available with each brand at some point in the future, the lack of immediate support at the launch of the unlocked iPhone 5 will deter many from considering the phone until they become available, leaving T-Mobile as the only viable prepaid service alternative until the other prepaid brands catch up and begin offering their own nanoSIMs, which may not be anytime soon.  StraightTalk has since confirmed on its Twitter account that it has no plans to offer nanoSIMs, while Net10, Tracfone and Simple Mobile still have yet to make official statements on the matter.

Because of the lack of immediate official support for nanoSIMs by the above  MVNOs, enterprising users have taken to the internet to download and offer guides on cutting full-size and microSIMs to nanoSIM sizing, with varying levels of success, prompting a quickly growing cottage industry for nanoSIM cards and cutting tools on ebay and Craigslist.

As things stand on the prepaid side, T-Mobile is the current best bet for iPhone 5 buyers that want some measure of official support for the device, while Tracfone has yet to make an official decision on support. Of course, things can change quickly and considering that Tracfone rolled out BYOD service as a result of the resourcefulness of an entire community, it’s only a matter of time before they do the same for nanoSIM and iPhone 5 support.