Recently I gave up on Android phones and got myself an iPhone 5. And because I wanted to stop paying ridiculous prices for cellular contracts, I made sure to get an unlocked GSM phone so I could use no-contract plans.
My first choice of carrier (T-Mobile) didn’t quite pan out, even though they currently have the cheapest “unlimited data” plan–I ran out of voice minutes in one day (with no call history to prove it), and their reception in my city was terrible! Thankfully, there’s no contract I have to wiggle out of, so I can just switch to a different GSM no-contract carrier such as Red Pocket Mobile.
Now, when I have the T-Mobile SIM card in, I can launch the iOS 6 Settings app and into General | Cellular | Cellular Data Network to change the APN, MMS Proxy, etc. without a problem.
…but when I put in my Red Pocket SIM card, the “Cellular Network Settings” section disappears!
Many people recommended unlockit.co.nz, which creates an Apple Configurator profile for your chosen network—but their profiles only sets the main APN (same as the profile provided by Red Pocket), and I needed to set the MMS APN, MMSC, and MMS Proxy, which are needed for text messages with pictures or multiple recipients.
I put my old T-Mobile SIM card into the phone and wait for it to detect.
Open the Settings app to General | Cellular | Cellular Data Network and leave it open.
Now eject the SIM card and put in my new Red Pocket one (or another AT&T MVNO like SimpleMobile).
Configure the MMS APN and related settings as instructed by my carrier.
Send a picture message to confirm it works.
Apparently I may have to do this process again after iOS updates, as frequently Apple’s update process deletes those settings.
Since switching my wireless carrier, I’ve been very pleased with Red Pocket Mobile, because they get better reception at my house and office since, as an MVNO, they’re using AT&T’s towers.
I can also get “frequent-flyer” discounts and occasional sales on their wireless refill cards from CallingMart.com. When you purchase a refill card, CallingMart.com will email you the PIN as soon as the transaction is made, so you can immediately apply the credit to your pay-as-you-go account. Highly recommended!
[Full disclosure: The Red Pocket and Calling Mart links are affiliate links, not in some desperate attempt to bilk you into clicking them, but because I believe (a) these are good companies and (b) someday maybe this website could pay for itself.]