This is another follow-up article based on my previously published post describing the difference between a text message and an iMessage. The original article has been quite popular and has generated some additional questions.
This article will address why text messages are delivered to an iPhone but not an iPad.
SMS/MMS Text Messages
Traditional text messages are sent through the cellular provider. You can not send or receive regular SMS/MMS text messages on a device that is not connected to a cellular network. Even if your iPad is 3G or 4G capable, it can not send or receive traditional SMS text messages. Your cellular provider delivers text messages using the cellular control channel of your phone. The iPad does not have access to the cellular control channel in this manner.
This may seem odd because iMessages can be sent and received on both iPhones and iPads. That’s because iMessage works differently than regular text messages.
Understanding iMessage Delivery
An iMessage can be delivered to an iPhone, iPad, iPod touch, or a Macintosh computer. This versatility is due to iMessage being related to your Apple ID. Any device that is setup to use your Apple ID is capable of sending or receiving iMessages. If you have an iPhone, the phone number is also associated with your Apple ID and all devices using the Apple ID can receive iMessages sent to your phone number.
When you send an iMessage, Apple will route that message through their servers using an Internet connection. This Internet connection can be either Wi-Fi or your cellular provider’s data network. This allows you to send iMessages from iPods, iPads, and Macintosh computers even without a traditional text messaging plan from a cellular provider.
Some people mistakenly think they have a text messaging problem because some messages appear on their iPhone and not their iPad. Usually, it is not a messaging problem, but rather they are seeing the difference in delivery between an iMessage and a regular text message.
*** UPDATE ***
With the release of iOS 8.1, Apple has included a feature called Text Message Forwarding, which will forward SMS text messages from the iPhone to the iPad. This allows SMS text messages to be sent and received in the Messages app on the iPad. This article provides additional information.
If you have additional questions about the Messages app, please see my other articles about text messages and iMessages.