Why cant i text on LG v520 tablet?

Tablets have a "phone number " for data access only.  It is not a phone, and cannot text with that number.  

You can sign up on the phone for ATT messages and add the app to the tablet to access text that way.  

Or use a 3rd party app which uses data to send messages.  They are not TEXT and not covered by a testing plan.

T-mobile is also not text, its data, and you have to sign up the phone or use an app.

Sorry, but your reply is inaccurate.

The T-Mobile version comes with a native android text app, and there's nothing that has to be done to make it text.

There is no app to download, and no "signing up the phone." 

In fact, there is no phone involved at all.  

I have four T-Mobile tablets, and two AT&T tablets.

All of the T-Mobile tablets can text with the native app that came installed.

Neither of the AT&T tablets can text.

Both AT&T and one of the T-Mobile tablets are the LG X Pad 8.0.

So, why do the AT&T tablets not allow text?

By the way, from a technical aspect, there are problems with your reply.  

Every cell-enabled device, phone, tablet, hot-spot, car monitor, etc., uses the "phone number" as an ID to connect to the network.  

The device uses the control channel within the cell signal to set up the connection, and maintain the connection as the device travels among cell zones.

It is on this control channel that SMS messages are sent and received. The original idea was based on the fact that the control channel has very little traffic as compared to the voice channel, so other information (in this case an SMS message) could be sent on that channel, using otherwise wasted bandwidth.

So, your assertion that the SMS travels over the network as data, is not entirely accurate.

Without the control channel, and the bandwith it has available for SMS message, no communications-- voice or data-- would be possible on a device.

It's been over a year and I still don't have a definitive answer on this!

Can some one please either tell me a solution, or give me a factual answer as to why I can't text on the AT&T version of this LG Tablet?

The T-Mobile version (V521) is a GSM LTE device, comes with a texting app, and is able to send and receive texts.

The AT&T Version (V520) is also a GSM, LTE device, but does not come with a texting app.

Same manufacturer, same technology, just different carriers!

Because Att sets it's service up different.  They want people to use numbersync

Thanks for the reply.

Maybe I wasn't clear, but I'm using the AT&T V520 tablet on T-Mobile, so what AT&T "wants" really has little to do with it, unless AT&T has somehow crippled the device hardware in order to prevent texting.

However, no one has been able to definitively state that the hardware is different between the V520 and V521.

Thanks!