Android gives users a whole lot of customization options, some of which are useful for everyone, while others are just for power users. One of these lower level settings is the Access Point Name—better known as the APN.
The APN is something most users won’t need to worry about. You pop your SIM card into your phone, maybe reboot it, and it connects to your carrier’s network. You’ll be able to make calls, send messages, browse dank memes, and other important things. But, if you still mess around with custom ROMs, or you’re using an MVNO, you may find that things don’t work automatically.
What is an Access Point Name (APN)?
The APN is all the information your phone uses to connect with your carrier’s network. It lists the address your phone uses to connect to the network, the ports used to handle Multimedia Messaging Service (MMS) messages, the type of data that particular APN uses, and other pieces of information to make sure your phone works correctly.
Some of the settings—-like “APN Type”—could be optional, and your phone will still work without it being 100% correct. Others like “MMSC” and “APN” are much more important, and your phone won’t function if they aren’t entered correctly.
Thankfully, most phones have the APN for common carriers built-in, so all you need to do is put your SIM card in and let your phone work its magic. This extends to some prepaid carriers as well: I use Mint Mobile, which runs on T-Mobile’s network. When I pop my SIM into my Google Pixel 2 XL or my Samsung Galaxy S8, it just works. The phones already have the APN, and it knows which one to load to connect to a given network.