What is a SIM adapter?

To understand what a SIM unlocking method is, you first need to differentiate between two concepts: iPhone Lock and iPhone World.

Currently, in the global market in general and the Vietnamese market in particular, the two most commonly used versions of iPhone are the locked iPhone (iPhone locked to a specific network) and the unlocked iPhone (iPhone unlocked internationally).

Locked iPhones are distributed to consumers through mobile carriers (AT&T, T-Mobile US, Softbank, Docomo, etc.) and require the purchase of an unlock code or a SIM adapter to fully utilize their functions. Locked iPhones are sold at a much lower price than the market price, making them a popular choice for consumers.

However, mobile carriers require buyers to sign a mobile contract and only use that one carrier. Users who want to use a different mobile network or take their iPhone abroad must unlock it.

What is a SIM adapter?

A SIM unlocking adapter is a solution for unlocking an iPhone using a flat chip that is installed over the user's SIM card. SIM unlocking adapters are commonly used on locked iPhones (iPhones sold with a carrier contract, only compatible with that carrier's SIM card).

With this method, the device will mistakenly believe that the SIM card you are using is valid, and the system will then allow the iPhone to perform normal functions like an international iPhone, including making calls, sending messages, and enabling 3G or 4G/LTE.

Additionally, another way to unlock an iPhone is to purchase an unlock code to make it an international version. After purchasing the unlock code, the locked iPhone will be activated as an international version. iPhone unlock codes are purchased directly from the carriers that distribute iPhones or through unlocking service providers.

However, compared to buying an unlock code to convert an iPhone to an international version, which costs from several hundred thousand to several million VND, using a SIM adapter for iPhones is much cheaper. Therefore, SIM adapters are chosen and used by a large number of users.

Advantages of SIM adapters

When using a SIM adapter, you can still use the original SIM tray instead of replacing it with a different one.

SIM adapters are inexpensive, easy to install, and easy to use.

SIM unlocking also supports many locked carriers around the world.

After installing the SIM adapter and getting a signal, the phone will function stably and have all the features of an international version.

Disadvantages of SIM adapters

iPhones using SIM adapters will not have as stable a signal as unlocked international versions, occasionally experiencing signal loss or weak signal. However, this rarely happens, and if it does, it's usually due to a very weak mobile network in the area.

Additionally, your phone will drain about 2% more battery than usual because it has to run the extra chip for the SIM adapter.

In addition, iPhones running iOS with a SIM adapter may experience some issues such as FaceTime, checking and topping up credit (*101#, *100#), and errors with +84 messages…